Investigate if we could provide a project generator instead of using `cargo-mobile2`

[fwcd]

There seems to be a fair bit of complexity around the generation machinery with cargo-mobile2 that we could avoid. Maybe it would be better to provide a project generator that generates Xcode/Android projects that users could commit directly? This repo could then contain an example output of the generator.

However, while committing the Xcode/Android projects it generally useful for downstream app projects¹, taking a template project and renaming everything is generally cumbersome, hence it might make this template repo less useful than it ought to be.

Footnotes

1. Since they likely want to customize more things than we, or projects like cargo-mobile2 with its mobile.toml, can anticipate, e.g. platform-specific app icons, entitlements etc. ↩