Add async/await as keywords in HLJS and codemirror

Author: ryyppy

plugins/cm-rescript-mode.js

@@ -36,7 +36,7 @@ CodeMirror.defineSimpleMode("rescript", {
       token: ["keyword", "keyword2", null, "def"]
     },
     {
-      regex: /(?:and|as|assert|catch|constraint|downto|else|exception|export|external|false|for|if|import|in|include|lazy|let|module|mutable|of|open|private|switch|to|true|try|type|when|while|with\!)\b/,
+      regex: /(?:and|as|assert|catch|async|await|constraint|downto|else|exception|export|external|false|for|if|import|in|include|lazy|let|module|mutable|of|open|private|switch|to|true|try|type|when|while|with\!)\b/,
       token: "keyword"
     },
     {

plugins/rescript-highlightjs.js

@@ -29,7 +29,7 @@ module.exports = function(hljs) {
     keyword:
       'and as assert catch constraint downto else exception export external false for ' +
       'if import in include lazy let module mutable of open private rec switch ' +
-      'to true try type when while with',
+      'to true try type when while with async await',
     // not reliable
      //built_in:
        //'array bool bytes char exn|5 float int int32 int64 list lazy_t|5 nativeint|5 ref string unit',