RFR: 8347033: [mobile] add ios-specific build docs [v4]

[Johan Vos]

On Mon, 24 Feb 2025 09:16:35 GMT, Abhinay Agarwal <duke at openjdk.org> wrote:

>> Adds build instruction for iOS
>
> Abhinay Agarwal has updated the pull request incrementally with one additional commit since the last revision:
> 
>   move documentation to README.md

looks good now. All comments seem to be addressed.

-------------

Marked as reviewed by jvos (Lead).

PR Review: https://git.openjdk.org/mobile/pull/34#pullrequestreview-2640896727