Add basic dev env setup guide (#2)

Add basic dev env setup guide

.idea/dictionaries/awarecan.xml

@@ -0,0 +1,8 @@
+<component name="ProjectDictionaryState">
+  <dictionary name="awarecan">
+    <words>
+      <w>firebase</w>
+      <w>tada</w>
+    </words>
+  </dictionary>
+</component>

README.md

@@ -1 +1,16 @@
-# 📱 Home Assistant Companion for Android
+# :iphone: Home Assistant Companion for Android
+
+## Setup Development Environment
+
+- Download and install [Android Studio](https://developer.android.com/studio)
+
+- Create a Firebase project at [Firebase Console](https://console.firebase.google.com)
+
+- Add an Android app to your Firebase project, follow the on screen instruction download the `google-services.json`
+  to your home-assistant-Android/app folder
+
+- Use Android Studio open your source code folder and click Run -> Run 'app'
+
+- Connect your phone or create a new virtual device following on screen instruction
+
+- :tada: