[automerger skipped] audio: Reformat README as Markdown am: 1074c22fe1 am: cbce6cefb4 am: ffcbe24f63 -s ours

am skip reason: Change-Id Ic6f60a21def4bf210a7e1446454d709f68a13422 with SHA-1 108e702dc7 is in history

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/1507218

Change-Id: Ic394b822c414dd25671664756a057413236a2148