MaxText 0.2.0 release notes and installation instructions

[bvandermoon]

Description

• Announce MaxText 0.2.0 release in README latest news
• Update installation instructions in ReadTheDocs
• Add Release Notes to ReadTheDocs
• Add specific commits to Github links that were missing them previously

Tests

N/A - documentation changes only

Checklist

Before submitting this PR, please make sure (put X in square brackets):

• I have performed a self-review of my code. For an optional AI review, add the gemini-review label.
• I have necessary comments in my code, particularly in hard-to-understand areas.
• I have run end-to-end tests tests and provided workload links above if applicable.
• I have made or will make corresponding changes to the doc if needed, including adding new documentation pages to the relevant Table of Contents (toctree directive) as explained in our documentation.