add ats mode from sublime package

.gitmodules

@@ -555,3 +555,9 @@
 [submodule "vendor/grammars/liquid.tmbundle"]
 	path = vendor/grammars/liquid.tmbundle
 	url = https://github.com/bastilian/validcode-textmate-bundles
+[submodule "ats-mode-sublimetext"]
+	path = ats-mode-sublimetext
+	url = https://github.com/steinwaywhw/ats-mode-sublimetext
+[submodule "vendor/grammars/ats.sublime"]
+	path = vendor/grammars/ats.sublime
+	url = https://github.com/steinwaywhw/ats-mode-sublimetext

grammars.yml

@@ -128,6 +128,8 @@ vendor/grammars/assembly.tmbundle:
 vendor/grammars/atom-salt:
 - source.python.salt
 - source.yaml.salt
+vendor/grammars/ats.sublime:
+- source.ats
 vendor/grammars/autoitv3-tmbundle:
 - source.autoit.3
 vendor/grammars/awk-sublime:

lib/linguist/languages.yml

@@ -82,10 +82,9 @@ ATS:
   - ats2
   extensions:
   - .dats
-  - .atxt
   - .hats
   - .sats
-  tm_scope: source.ocaml
+  tm_scope: source.ats
   ace_mode: ocaml
 
 ActionScript: