Add coffee linter

ale_linters/coffee/coffee.vim

@@ -0,0 +1,17 @@
+" Author: KabbAmine - https://github.com/KabbAmine
+" Description: Coffee for checking coffee files
+
+if exists('g:loaded_ale_linters_coffee_coffee')
+    finish
+endif
+
+let g:loaded_ale_linters_coffee_coffee = 1
+
+call ALEAddLinter('coffee', {
+\   'name': 'coffee',
+\   'executable': 'coffee',
+\   'command': 'coffee -cp -s',
+\   'output_stream': 'stderr',
+\   'callback': 'ale#handlers#HandleGCCFormat',
+\})
+