Update formatting.

README.md

@@ -34,10 +34,10 @@ ODK Collect renders forms that are compliant with the [ODK XForms standard](http
 
 To run functionality that makes API calls from your debug-signed builds, you may need to get an API key or otherwise authorize your app.
 
-### Google Drive API
+#### Google Drive API
 Follow the instructions in the "Generate the signing certificate fingerprint and register your application" section from [here](https://developers.google.com/drive/android/auth). Enable the Google Drive API [here](https://console.developers.google.com/apis/api/drive/).
 
-### Google Maps API
+#### Google Maps API
 Follow the instructions [here](https://developers.google.com/maps/documentation/android-api/signup). Please be sure not to commit your personal API key to a branch that you will submit a pull request for.
 
 ## Contributing code