[llvm] [BOLT][NFC] Add documentation on BOLT options (PR #92117)

[Elvina Yakubova via llvm-commits]

ElvinaYakubova wrote:

> Great! Thank you. Is there a plan on synchronizing this document with new options or modifications to existing options?

Synchronization sounds like a good next step, I think I'll work on a script to automate the process 

https://github.com/llvm/llvm-project/pull/92117