Restructure docs for KTX

Author: samtstern

.opensource/project.json

@@ -4,13 +4,22 @@
     "platforms": [
         "Android"
     ],
-    "content": "README.md",
-    "pages": [
-        "firebase-common/README.md",
-        "firebase-firestore/README.md",
-        "protolite-well-known-types/README.md"
-    ],
+    "content": "docs/README.md",
+    "pages": {
+        "README.md": "Development Guide",
+        "docs/ktx/firestore.md": "Firestore KTX"
+    },
     "related": [
         "firebase/quickstart-android"
+    ],
+    "tabs": [
+        {
+            "title": "Main Reference",
+            "href": "https://firebase.google.com/docs/reference/android/"
+        },
+        {
+            "title": "KTX Reference",
+            "href": "https://firebase.github.io/firebase-android-sdk/reference/kotlin/firebase-ktx/"
+        }
     ]
 }

docs/README.md

@@ -0,0 +1,26 @@
+# Firebase Android SDK
+
+The Firebase SDK for Android is the official way to add Firebase to your
+Android app. To get started, visit the [setup instructions][android-setup].
+
+## Open Source
+
+The following Firebase SDKs for Android are developed in this
+repository:
+
+  * `firebase-common`
+  * `firebase-database`
+  * `firebase-firestore`
+  * `firebase-functions`
+  * `firebase-inappmessaging-display`
+  * `firebase-storage`
+
+For more information on building the SDKs from source or contributing,
+visit the [main README][main-readme].
+
+## Kotlin Extensions
+
+
+
+[android-setup]: https://firebase.google.com/docs/android/setup
+[main-readme]: https://github.com/firebase/firebase-android-sdk/blob/master/README.md

docs/ktx/firestore.md

@@ -0,0 +1,5 @@
+# Firestore Kotlin Extensions
+
+```
+// TODO: Finish this page
+```