RFC 1 Updates

[joshmoore]

This PR updates RFC 1 in the following ways:

• [x] Lists current reviewers and commenters
• [x] Adds a legend for symbols like 🕑 and 📂
• [x] Adds a section on decision-making
• [x] Add a changelog to the RFC

It additionally:

• [x] removes the previous use of the term "Editor" throughout the specification to prevent confusion
• ~[ ] clarifies how to suggest someone in particular (including oneself) as a reviewer~

[github-actions[bot]]

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