Add cson extension to coffeescript, closes #639

Co-authored-by: Collin Styles <collin.styles@mycase.com>

README.md

@@ -59,7 +59,7 @@ On top of all language packs from [vim repository](https://github.com/vim/vim/tr
 - [cjsx](https://github.com/mtscout6/vim-cjsx)
 - [clojure](https://github.com/guns/vim-clojure-static) (Clojure syntax highlighting for clj, boot, cl2, cljc, cljs, cljs.hl, cljscm, cljx, hic and edn files)
 - [cmake](https://github.com/pboettch/vim-cmake-syntax) (CMake syntax highlighting for cmake and cmake.in files)
-- [coffee-script](https://github.com/kchmck/vim-coffee-script) (CoffeeScript and Literate CoffeeScript syntax highlighting for coffee, cake, cjsx, iced, coffeekup, litcoffee and coffee.md files)
+- [coffee-script](https://github.com/kchmck/vim-coffee-script) (CoffeeScript and Literate CoffeeScript syntax highlighting for coffee, cake, cjsx, iced, coffeekup, cson, litcoffee and coffee.md files)
 - [cpp-modern](https://github.com/bfrg/vim-cpp-modern)
 - [cql](https://github.com/elubow/cql-vim) (Syntax highlighting for cql files)
 - [cryptol](https://github.com/victoredwardocallaghan/cryptol.vim) (Syntax highlighting for cry, cyl, lcry and lcyl files)

autoload/polyglot/sleuth.vim

@@ -81,7 +81,7 @@ let s:globs = {
   \ 'cmusrc': '',
   \ 'cobol': '*.cbl,*.cob,*.lib',
   \ 'coco': '*.atg',
-  \ 'coffee': '*.coffee,*._coffee,*.cake,*.cjsx,*.iced,*.coffeekup,Cakefile',
+  \ 'coffee': '*.coffee,*._coffee,*.cake,*.cjsx,*.iced,*.coffeekup,*.cson,Cakefile',
   \ 'conaryrecipe': '*.recipe',
   \ 'conf': '*.conf,auto.master,config',
   \ 'config': 'configure.in,configure.ac,Pipfile',

ftdetect/polyglot.vim

@@ -2441,7 +2441,7 @@ if !has_key(g:polyglot_is_disabled, 'cryptol')
 endif
 
 if !has_key(g:polyglot_is_disabled, 'coffee-script')
-  au BufNewFile,BufRead *._coffee,*.cake,*.cjsx,*.coffee,*.coffeekup,*.iced,Cakefile setf coffee
+  au BufNewFile,BufRead *._coffee,*.cake,*.cjsx,*.coffee,*.coffeekup,*.cson,*.iced,Cakefile setf coffee
   au BufNewFile,BufRead *.coffee.md,*.litcoffee setf litcoffee
 endif
 

packages.yaml

@@ -403,6 +403,7 @@ filetypes:
   extra_extensions:
   # 17 results: https://github.com/search?q=extension%3Acoffeekup+html&type=Code
   - coffeekup
+  - cson
   ignored_warnings:
   # Probably mistake
   - '*Cakefile'