Additional polish (#41)

* Add more specific classNames for user styling
* Update graphiql class names (these were changed upstream)
* - Deprecated fields have a special class name for styling
- Fix buttons at the bottom for less scrolling, and they also take up less space
- `__typename` will be automatically removed if it’s not the only field selection (only at the top level) and added back in if there are no other fields
* Reword slightly, move attribution

Author: sgrove