Specify language for more code blocks in README (#375)

README.md

@@ -57,7 +57,7 @@ compiler errors.
 Usage
 -----
 
-```sh
+```
 $ tippecanoe -o file.mbtiles [options] [file.json file.json.gz file.fgb ...]
 ```
 
@@ -99,7 +99,7 @@ $ tippecanoe -o alameda.mbtiles -l alameda -n "Alameda County from TIGER" -z13 t
 Create a tileset of all TIGER roads, at only zoom level 12, but with higher detail than normal,
 with a custom layer name and description, and leaving out the `LINEARID` and `RTTYP` attributes:
 
-```
+```sh
 $ cat tiger/tl_2014_*_roads.json | tippecanoe -o tiger.mbtiles -l roads -n "All TIGER roads, one zoom" -z12 -Z12 -d14 -x LINEARID -x RTTYP
 ```
 
@@ -108,7 +108,7 @@ Cookbook
 
 ### Linear features (world railroads), visible at all zoom levels
 
-```
+```sh
 curl -L -O https://www.naturalearthdata.com/http//www.naturalearthdata.com/download/10m/cultural/ne_10m_railroads.zip
 unzip ne_10m_railroads.zip
 ogr2ogr -f GeoJSON ne_10m_railroads.geojson ne_10m_railroads.shp
@@ -122,7 +122,7 @@ tippecanoe -zg -o ne_10m_railroads.mbtiles --drop-densest-as-needed --extend-zoo
 
 ### Discontinuous polygon features (buildings of Rhode Island), visible at all zoom levels
 
-```
+```sh
 curl -L -O https://usbuildingdata.blob.core.windows.net/usbuildings-v1-1/RhodeIsland.zip
 unzip RhodeIsland.zip
 
@@ -135,7 +135,7 @@ tippecanoe -zg -o RhodeIsland.mbtiles --drop-densest-as-needed --extend-zooms-if
 
 ### Continuous polygon features (states and provinces), visible at all zoom levels
 
-```
+```sh
 curl -L -O https://www.naturalearthdata.com/http//www.naturalearthdata.com/download/10m/cultural/ne_10m_admin_1_states_provinces.zip
 unzip -o ne_10m_admin_1_states_provinces.zip
 ogr2ogr -f GeoJSON ne_10m_admin_1_states_provinces.geojson ne_10m_admin_1_states_provinces.shp
@@ -149,7 +149,7 @@ tippecanoe -zg -o ne_10m_admin_1_states_provinces.mbtiles --coalesce-densest-as-
 
 ### Large point dataset (GPS bus locations), for visualization at all zoom levels
 
-```
+```sh
 curl -L -O ftp://avl-data.sfmta.com/avl_data/avl_raw/sfmtaAVLRawData01012013.csv
 sed 's/PREDICTABLE.*/PREDICTABLE/' sfmtaAVLRawData01012013.csv > sfmta.csv
 tippecanoe -zg -o sfmta.mbtiles --drop-densest-as-needed --extend-zooms-if-still-dropping sfmta.csv
@@ -163,7 +163,7 @@ tippecanoe -zg -o sfmta.mbtiles --drop-densest-as-needed --extend-zooms-if-still
 
 ### Clustered points (world cities), summing the clustered population, visible at all zoom levels
 
-```
+```sh
 curl -L -O https://www.naturalearthdata.com/http//www.naturalearthdata.com/download/10m/cultural/ne_10m_populated_places.zip
 unzip -o ne_10m_populated_places.zip
 ogr2ogr -f GeoJSON ne_10m_populated_places.geojson ne_10m_populated_places.shp
@@ -178,7 +178,7 @@ tippecanoe -zg -o ne_10m_populated_places.mbtiles -r1 --cluster-distance=10 --ac
 
 ### Show countries at low zoom levels but states at higher zoom levels
 
-```
+```sh
 curl -L -O https://www.naturalearthdata.com/http//www.naturalearthdata.com/download/10m/cultural/ne_10m_admin_0_countries.zip
 unzip ne_10m_admin_0_countries.zip
 ogr2ogr -f GeoJSON ne_10m_admin_0_countries.geojson ne_10m_admin_0_countries.shp
@@ -206,7 +206,7 @@ States and Provinces:
 
 ### Represent multiple sources (Illinois and Indiana counties) as separate layers
 
-```
+```sh
 curl -L -O https://www2.census.gov/geo/tiger/TIGER2010/COUNTY/2010/tl_2010_17_county10.zip
 unzip tl_2010_17_county10.zip
 ogr2ogr -f GeoJSON tl_2010_17_county10.geojson tl_2010_17_county10.shp
@@ -224,7 +224,7 @@ tippecanoe -zg -o counties-separate.mbtiles --coalesce-densest-as-needed --exten
 
 ### Merge multiple sources (Illinois and Indiana counties) into the same layer
 
-```
+```sh
 curl -L -O https://www2.census.gov/geo/tiger/TIGER2010/COUNTY/2010/tl_2010_17_county10.zip
 unzip tl_2010_17_county10.zip
 ogr2ogr -f GeoJSON tl_2010_17_county10.geojson tl_2010_17_county10.shp
@@ -242,7 +242,7 @@ As above, but
 
 ### Selectively remove and replace features (Census tracts) to update a tileset
 
-```
+```sh
 # Retrieve and tile California 2000 Census tracts
 curl -L -O https://www2.census.gov/geo/tiger/TIGER2010/TRACT/2000/tl_2010_06_tract00.zip
 unzip tl_2010_06_tract00.zip
@@ -316,7 +316,7 @@ If your input is formatted as newline-delimited GeoJSON, use `-P` to make input
  * `-L` _name_`:`_file.json_ or `--named-layer=`_name_`:`_file.json_: Specify layer names for individual files. If your shell supports it, you can use a subshell redirect like `-L` _name_`:<(cat dir/*.json)` to specify a layer name for the output of streamed input.
  * `-L{`_layer-json_`}` or `--named-layer={`_layer-json_`}`: Specify an input file and layer options by a JSON object. The JSON object must contain a `"file"` key to specify the filename to read from. (If the `"file"` key is an empty string, it means to read from the standard input stream.) It may also contain a `"layer"` field to specify the name of the layer, and/or a `"description"` field to specify the layer's description in the tileset metadata, and/or a `"format"` field to specify `csv` or `fgb` file format if it is not obvious from the `name`. Example:
 
-```
+```sh
 tippecanoe -z5 -o world.mbtiles -L'{"file":"ne_10m_admin_0_countries.json", "layer":"countries", "description":"Natural Earth countries"}'
 ```
 
@@ -433,20 +433,20 @@ be reduced to the maximum that can be used with the specified _maxzoom_.
 
 Example: to find the Natural Earth countries with low `scalerank` but high `LABELRANK`:
 
-```
+```sh
 tippecanoe -z5 -o filtered.mbtiles -j '{ "ne_10m_admin_0_countries": [ "all", [ "<", "scalerank", 3 ], [ ">", "LABELRANK", 5 ] ] }' ne_10m_admin_0_countries.geojson
 ```
 
 Example: to retain only major TIGER roads at low zoom levels:
 
-```
+```sh
 tippecanoe -o roads.mbtiles -j '{ "*": [ "any", [ ">=", "$zoom", 11 ], [ "in", "MTFCC", "S1100", "S1200" ] ] }' tl_2015_06001_roads.json
 ```
 
 Tippecanoe also accepts expressions of the form `[ "attribute-filter", name, expression ]`, to filter individual feature attributes
 instead of entire features. For example, you can exclude the road names at low zoom levels by doing
 
-```
+```sh
 tippecanoe -o roads.mbtiles -j '{ "*": [ "attribute-filter", "FULLNAME", [ ">=", "$zoom", 9 ] ] }' tl_2015_06001_roads.json
 ```
 
@@ -597,7 +597,7 @@ contain `index`, `sequence`, `extent`, and `dropped`, elements, which must be pa
  * Make a tileset of the Natural Earth countries to zoom level 5, and also copy the GeoJSON features
    to files in a `tiles/z/x/y.geojson` directory hierarchy.
 
-```
+```sh
 tippecanoe -o countries.mbtiles -z5 -C 'mkdir -p tiles/$1/$2; tee tiles/$1/$2/$3.geojson' ne_10m_admin_0_countries.json
 ```
 
@@ -605,13 +605,13 @@ tippecanoe -o countries.mbtiles -z5 -C 'mkdir -p tiles/$1/$2; tee tiles/$1/$2/$3
    intersect the [bounding box of Germany](https://www.flickr.com/places/info/23424829).
    (The `limit-tiles-to-bbox` script is [in the Tippecanoe source directory](filters/limit-tiles-to-bbox).)
 
-```
+```sh
 tippecanoe -o countries.mbtiles -z5 -C './filters/limit-tiles-to-bbox 5.8662 47.2702 15.0421 55.0581 $*' ne_10m_admin_0_countries.json
 ```
 
  * Make a tileset of TIGER roads in Tippecanoe County, leaving out all but primary and secondary roads (as [classified by TIGER](https://www.census.gov/geo/reference/mtfcc.html)) below zoom level 11.
 
-```
+```sh
 tippecanoe -o roads.mbtiles -c 'if [ $1 -lt 11 ]; then grep "\"MTFCC\": \"S1[12]00\""; else cat; fi' tl_2016_18157_roads.json
 ```
 
@@ -628,7 +628,7 @@ Tippecanoe defines a GeoJSON extension that you can use to specify the minimum a
 at which an individual feature will be included in the vector tileset being produced.
 If you have a feature like this:
 
-```
+```json
 {
     "type" : "Feature",
     "tippecanoe" : { "maxzoom" : 9, "minzoom" : 4 },
@@ -649,7 +649,7 @@ dropped it.
 You can also specify a layer name in the `tippecanoe` object, which will take precedence over
 the filename or name specified using `--layer`, like this:
 
-```
+```json
 {
     "type" : "Feature",
     "tippecanoe" : { "layer" : "streets" },
@@ -722,7 +722,7 @@ Tippecanoe now requires features from the 2011 C++ standard. If your compiler is
 that, you will need to install a newer one. On MacOS, updating to the latest XCode should
 get you a new enough version of `clang++`. On Linux, you should be able to upgrade `g++` with
 
-```
+```sh
 sudo add-apt-repository -y ppa:ubuntu-toolchain-r/test
 sudo apt-get update -y
 sudo apt-get install -y g++-5
@@ -858,7 +858,7 @@ awk 'BEGIN {
 
 which looks like this:
 
-```
+```csv
 GEOID10,population
 "060014277003018",0
 "060014283014046",0
@@ -956,7 +956,7 @@ for Tippecanoe County, Indiana.
 
 Download Census block geometry, and convert to GeoJSON:
 
-```
+```sh
 $ curl -L -O https://www2.census.gov/geo/tiger/TIGER2010/TABBLOCK/2010/tl_2010_18157_tabblock10.zip
 $ unzip tl_2010_18157_tabblock10.zip
 $ ogr2ogr -f GeoJSON tl_2010_18157_tabblock10.json tl_2010_18157_tabblock10.shp
@@ -964,7 +964,7 @@ $ ogr2ogr -f GeoJSON tl_2010_18157_tabblock10.json tl_2010_18157_tabblock10.shp
 
 Download Indiana employment data, and fix name of join key in header
 
-```
+```sh
 $ curl -L -O https://lehd.ces.census.gov/data/lodes/LODES7/in/wac/in_wac_S000_JT00_2015.csv.gz
 $ gzip -dc in_wac_S000_JT00_2015.csv.gz | sed '1s/w_geocode/GEOID10/' > in_wac_S000_JT00_2015.csv
 ```
@@ -972,13 +972,13 @@ $ gzip -dc in_wac_S000_JT00_2015.csv.gz | sed '1s/w_geocode/GEOID10/' > in_wac_S
 Sort GeoJSON block geometry so it is ordered by block ID. If you don't do this, you will get a
 "GeoJSON file is out of sort" error.
 
-```
+```sh
 $ tippecanoe-json-tool -e GEOID10 tl_2010_18157_tabblock10.json | LC_ALL=C sort > tl_2010_18157_tabblock10.sort.json
 ```
 
 Join block geometries to employment attributes:
 
-```
+```sh
 $ tippecanoe-json-tool -c in_wac_S000_JT00_2015.csv tl_2010_18157_tabblock10.sort.json > blocks-wac.json
 ```