document parserOpts

Author: goto-bus-stop

package.json

@@ -13,7 +13,7 @@
     "through2": "^2.0.0"
   },
   "devDependencies": {
-    "browserify": "^4.2.0",
+    "browserify": "^16.1.1",
     "concat-stream": "^1.6.0",
     "tap": "~0.4.8",
     "through": "^2.3.4"

readme.markdown

@@ -125,6 +125,9 @@ Optionally, you can set which `opts.vars` will be used in the
 [static argument evaluation](https://npmjs.org/package/static-eval)
 in addition to `__dirname` and `__filename`.
 
+`opts.parserOpts` can be used to configure the parser brfs uses,
+[acorn](https://github.com/acornjs/acorn#main-parser).
+
 # events
 
 ## tr.on('file', function (file) {})