Expand README even more

Author: Mygod

README.md

@@ -10,3 +10,21 @@ Run rooted Kotlin JVM code made super easy with coroutines and parcelize!
 Check out demo at `app` to see just how easy it is.
 Also check out more complicated demos:
 * [VPN Hotspot](https://github.com/Mygod/VPNHotspot)
+
+## Features
+
+* Supports coroutines
+* Persistent root session that closes itself on inactive (optional and configurable)
+* Works around not able to `exec` on certain devices running Android 5-7.1
+  (See `RootServer.init#shouldRelocate` if you need this feature)  
+
+## Private APIs used
+
+The following private platform APIs are invoked if you use `shouldRelocate = true` on Android 10+.
+(So never under normal circumstances.)
+API restrictions are updated up to [SHA-256 checksum `2886a24b6382be8751e86e3c355516c448987c3b0550eb8bb906a34490cfaa3c`](https://dl.google.com/developers/android/tm/non-sdk/hiddenapi-flags.csv).
+
+* `Landroid/os/SystemProperties;->get(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/String;,sdk,system-api,test-api`
+* `Landroid/os/SystemProperties;->getBoolean(Ljava/lang/String;Z)Z,sdk,system-api,test-api`
+* `Ldalvik/system/VMRuntime;->getCurrentInstructionSet()Ljava/lang/String;,core-platform-api,unsupported`
+* `Ldalvik/system/VMRuntime;->getRuntime()Ldalvik/system/VMRuntime;,core-platform-api,unsupported`