- Merge guide.md updates from GitHub.
- Update Opus repository.
- Fix missing link in Opus README.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=122080285
GitHub note - Apologies for the cryptic change descriptions,
they relate to a design doc that's not externally visible.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=113043764