docs: [DOCS-3549] Rename Change Feeds to Event Feeds

[jrodewig]

Renames Changed Feeds to Event Feeds in the README and comments.

Description

• Renames Changed Feeds to Event Feeds in the README and comments.
• Move the Change Feeds section before the Event Streaming section in the README (per Product request)

I'll merge this PR at the same time as documentation changes go live.

Motivation and context

Align with our documentation and marketing

How was the change tested?

N/A

Screenshots (if appropriate):

Change types

• • Bug fix (non-breaking change that fixes an issue)
• • New feature (non-breaking change that adds functionality)
• • Breaking change (backwards-incompatible fix or feature)

Checklist:

• • My code follows the code style of this project.
• • My change requires a change to Fauna documentation.
• • My change requires a change to the README, and I have updated it accordingly.

---

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.