Added Tusky-API and Firebase basic info to README.md.

README.md

@@ -17,13 +17,20 @@ It is currently available on [Google Play](https://play.google.com/store/apps/de
 My Mastodon account is [Vavassor@mastodon.social](https://mastodon.social/users/Vavassor).
 
 ## Building
-
-### Dependencies
-- Java Development Kit 7 or higher
-- Android SDK
+The most basic things needed are the Java Development Kit 7 or higher and the Android SDK.
 
 The project uses [the Gradle build system](https://gradle.org). Android studio uses Gradle by default, so it'd be straightforward to import this repository using your chosen version control software from the menu:
 <pre>VCS > Checkout from version control > Git/SVN/Mercurial</pre>
 After making it into an android studio project you can build/run as you wish.
 
 It's also possible to build using Gradle by itself on the command line if you have it installed and configured. This repository includes a gradle wrapper script that can be used, following this guide [Build You App On The Command Line](https://developer.android.com/studio/build/building-cmdline.html).
+
+The project's gradle files describe its building needs more in-depth and dependencies can be found in app/build.gradle.
+
+### Firebase
+
+This app uses Firebase's Cloud Messaging and Crash Reporting, so in order to build it, a Firebase project has to be made and associated with the build by including a google-services.json file in the app/ directory.
+
+### Tusky-API
+
+Tusky uses its own server for push notifications, the [tusky-api server](https://github.com/Gargron/tusky-api). This system works with Firebase and the Tusky-API server in tandem. After that is set up as per its directions, the only thing needed to call the server in this project is to give its URL to the string tusky_web_url in the file app/src/main/res/values/donottranslate.xml .