Use begin/end patterns for // comments

This allows injections grammars to match in between
such as the language-todo package.
Closesatom/language-todo#31

Author: kevinsawicki

grammars/go.cson

@@ -18,9 +18,10 @@
  }
  {
 'comment':'Line comments'
-'match':'(//).*$\\n?'
-'captures':
-'1':
+'begin':'//'
+'end':'$'
+'beginCaptures':
+'0':
 'name':'punctuation.definition.comment.go'
 'name':'comment.line.double-slash.go'
  }