* Edgchen1/objc api reference 1.9 (#1)
* Update Objective-C API reference for 1.9.
* Update spelling.
* Test link changes.
* Fix links.
* Fix links and updates in mobile-performance-tuning.md.
* Fix links in tutorials/mobile/custom-build.md.
* Fix
* Fix
* Fix links in docs/tutorials/mobile/initial-setup.md.
* Fix links.
* Update note.
* Add 1.9 op type support page.
* Add nav info to page.
* Rename files to not have spaces.
* Update ORT Mobile documentation for both the pre-built package and custom build usage
Add info on pre-built package and CoreML EP
Refer to operator kernels and contrib ops documentation in github so we can point to the version specific content
Tweak some aspects like not specifying nav_order in places (items sort alphabetically by default)
* merge previous unmerged ios doc updates
* Address PR comments
* Minor tweaks
* Address PR comments
Co-authored-by: Guoyu Wang <wanggy@outlook.com>