docs: fix typos and grammar in guidelines

[Avicennasis]

Summary

Fixes 10 typos / grammar errors across 3 documentation files in docs/:

docs/DEPRECATE-GUIDELINES.md

• ie: -> i.e.: (3 occurrences - abbreviation punctuation)
• There are some ongoing discussion -> ongoing discussions
• If there're no responses -> If there are no responses

docs/governance.md

• This may the case with projects -> This may be the case with projects
• expectations around writing unit test, -> writing unit tests,
• all further decision making. (technical or otherwise). -> all further decision making (technical or otherwise). (stray sentence-ending period before the parenthetical)

docs/PUBLISH-GUIDELINES.md

• but it also offer two methods -> but it also offers two methods
• Use one base on your preference -> Use one based on your preference (markdown table column padding adjusted by one space so the table stays aligned)

No functional changes - documentation prose only. No identifiers, code samples, or command strings were altered.

The commit is signed off per the Developer's Certificate of Origin 1.1 in CONTRIBUTING.md.