[Docs] Tree-shaking benchmark of RN app

## Summary

Add page to docs that will showcase potential gains obtained through the use of tree-shaking.

We could also add few tips how to optimize the codebase to squeeze even more out of tree-shaking, also backed with data.

The issue names no files, tests, or benchmark entry point. Start by locating the documentation page structure and the React Native tree-shaking benchmark setup; define the measured data and optimization tips before adding the page and confirming the documented gains.

Written by the indexing model from the issue text.