message: Improve "contributing" docs
diff: Make a PR!
  -To enable the handbook locally, add the following to your `ember-osf-web/config/local.js`:
  +## Running the handbook locally
  +1. Add the following to your `ember-osf-web/config/local.js`:
  ```js
  module.exports = {
  HANDBOOK_ENABLED: true,
  };
  ```
  +1. Add `/handbook/` to the `routes` list in `osf.io/website/ember_osf_web/views.py`
  +1. Go to `localhost:5000/handbook/`
  -## Adding a docs page
  +## Adding a handbook page
  These pages are nice, friendly markdown files that live in `lib/handbook/addon/docs/`.
  To add a new page:
  