Android Docs should state that exported APK file will only work on devices with Android 11+

I spent... most of today trying to figure out why my builds aren't working. I was going to test them on my old phone which runs Android 10. Adding to the docs that the output APK file will only be able to be installed/tested/debugged on android 11 or higher would've assisted me.

Personally I would add the requirements right after this:
Exporting for Android has fewer requirements than compiling Godot for Android. The requirements are:

- An Android device using android 11.0+
- Android SDK
- OpenJDK
- Debugkey (and releasekey if you want to release)
- Setting it up in Godot
- etc. then go into the steps

The following steps detail what is needed to set up the Android SDK and the engine.