add instruction on how to update jshint lib

tool/Readme.md

@@ -23,4 +23,18 @@ node add_mode.js ModeName "extension1|extension2|^FullName"
 
 ```
 node tmlanguage.js ./templates/dummy.JSON-tmLanguage
-```
+```
+
+# update_deps.js
+To update `jshint` to new version:
+1. Clone last version from https://github.com/jshint/jshint
+2. Replace all `lodash` with `underscore` in requires in `jshint/src/*.js`
+3. Add `_.slice = require("lodash.slice");` to `src/scope-manager.js` after `var _ = ...`
+4. Add `_.clone = require("lodash.clone");` to `src/jshint.js` after `var _ = ...`
+5. Add ```  
+   "underscore": latest
+   "lodash.clone": "^4.5.0",
+   "lodash.slice": "^4.2.0"
+   ``` to `package.json`, remove `lodash` and run `npm i`
+6. Change in `ace/tool/update_deps.js` jshint path `deps.jshint.browserify.path` with your path to changed jshint
+7. Run `node update_deps.js jshint`