Support escape in tagged templates

Author: DZakh

Diff for: grammars/rescript.tmLanguage.json

@@ -160,6 +160,10 @@
             }
           },
           "patterns": [
+            {
+              "name": "constant.character.escape",
+              "match": "\\\\."
+            },
             {
               "name": "meta.template.expression",
               "begin": "\\$\\{",
@@ -606,4 +610,4 @@
       "include": "#defaultIdIsVariable"
     }
   ]
-}
+}