Document Android controls

[oong819]

Add compact, short information about your PR for easier understanding:

• Goal of the PR
  make Android docs up to date and use Markdown
  improve control document
• How does the PR work?
  Text changing
• Does it resolve any reported issue?
  Android: Document use of controls when interacting with inventory (plus some controls discussion) #8729
• Does this relate to a goal in the roadmap?
  seems not
• If not a bug fix, why is this PR needed? What usecases does it solve?
  improve doc

To do

This PR is Ready

• Check the information (correct?)
• Check grammar

How to test

Check Android root directory (root is NOT required)
Check in-game

[oong819]

what minimum Android version recommended for Minetest?

[rollerozxa]

Minimum is API level 14 (Android 4.1), but there is no recommended version (other than one that still gets security updates by Google, Android 10+)

[oong819]

Changed

[oong819]

forgot to change API level, now changed

[oong819]

i think the doc can be extend more, also previously waiting for review is long so i want to finish this with 1 PR

also seem like no one care the Android doc

[oong819]

i think its now ready

[SmallJoker]

There seem to be a few grammatical and stylistic issues in the document. Might it be possible for you to run a grammar checker on this file to improve the quality?

[oong819]

Minetest dont use Android widget view right?

[oong819]

final change: rename file from "Android.md" to "android.md" cuz other doc file are all lowercase, only special file have some uppercase character

[oong819]

if no problem, merge pls?