docs(readme): add Discord community link and badge

[KnockOutEZ]

Adds the Discord community invite to the README's top section:

• Discord badge alongside the existing badges
• Discord entry in the top nav line
• one-line community callout under the nav

Docs-only change — no code, no behaviour change.

Invite: https://discord.gg/BkUUgz2bNF

Summary by CodeRabbit

• Documentation
  • Updated the README with a Discord badge and community link.
  • Added Discord to the project navigation and community callout.

[coderabbitai]

Caution

Review failed

The pull request is closed.

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Advanced

Run ID: 06b81ef3-043c-4554-80e6-d798513b0652

📥 Commits

Reviewing files that changed from the base of the PR and between c6ad447 and 7b67309.

📒 Files selected for processing (1)

• README.md

---

📝 Walkthrough

Walkthrough

The README now includes Discord references in the badges, top navigation, and community callout.

Changes

Community navigation

Layer / File(s)	Summary
Add Discord README links README.md	The README adds a Discord badge, a Discord navigation link, and a community invitation.

Estimated code review effort: 1 (Trivial) | ~2 minutes

Change: Other

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch docs/readme-discord-community

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}