Rationale update for all basleines

[snarve]

💡 Summary

This epic covers the rationale updates for all the baselines

Motivation and context

Implementation notes

Update rationale statements for all the baselines

• [x] Chat - https://github.com/cisagov/ScubaGoggles/issues/229
• [x] Sites
• [x] Meet
• [x] Calendar
• [x] Gmail - https://github.com/cisagov/ScubaGoggles/issues/228
• [x] Common Controls - https://github.com/cisagov/ScubaGoggles/issues/230
• [x] Groups - https://github.com/cisagov/ScubaGoggles/issues/231
• [x] Drive Docs - https://github.com/cisagov/ScubaGoggles/issues/232

Acceptance criteria

• [ ] All baselines have updated rationale