Add Google Firebase (#2652)

README.md

@@ -459,6 +459,7 @@ API | Description | Auth | HTTPS | CORS |
 | [Gitter](https://developer.gitter.im/docs/welcome) | Chat for Developers | `OAuth` | Yes | Unknown |
 | [Glitterly](https://developers.glitterly.app) | Image generation API | `apiKey` | Yes | Yes |
 | [Google Docs](https://developers.google.com/docs/api/reference/rest) | API to read, write, and format Google Docs documents | `OAuth` | Yes | Unknown |
+| [Google Firebase](https://firebase.google.com/docs) | Google's mobile application development platform that helps build, improve, and grow app | `apiKey` | Yes | Yes |
 | [Google Fonts](https://developers.google.com/fonts/docs/developer_api) | Metadata for all families served by Google Fonts | `apiKey` | Yes | Unknown |
 | [Google Keep](https://developers.google.com/keep/api/reference/rest) | API to read, write, and format Google Keep notes | `OAuth` | Yes | Unknown |
 | [Google Sheets](https://developers.google.com/sheets/api/reference/rest) | API to read, write, and format Google Sheets data | `OAuth` | Yes | Unknown |