docs: fix numbered lists and spelling in CONTRIBUTING.md

[D-Gaspa]

Summary

While reviewing the contributing guidelines, I noticed some minor formatting and spelling issues that could be improved:

• The numbered lists in several sections use repeated "1." instead of sequential numbering (2, 3, 4)
• "Chose" is used instead of "Choose" in the publishing workflow section

This PR fixes these small issues to improve readability of the documentation.

Test Plan

Documentation-only change that doesn't require functional testing. I've visually verified that the Markdown renders correctly with these changes.

Checklist

• Documentation is up to date.
• Follows commit message convention described in CONTRIBUTING.md.
• For functional changes, my test plan has linked these CLI changes into a local react-native checkout (instructions).
  (Not applicable as this is a documentation-only change)