Description

Add the Slack community invite badge to the documentation site's index page (docs/src/index.md) to match the badge added to the main README.

Context

The Slack badge was added to the main README.md in PR #1418. For consistency, it should also be added to the documentation site index at the community links section (around lines 100-105).

Reference

• File: docs/src/index.md
• Location:

  clp/docs/src/index.md

  Lines 100 to 105 in 56ebca1

  	## Community
  	Need help? Join us on one of our community servers:
  	* [![Discord][badge-discord]][yscope-community-discord]
  	* [![CLP on Zulip][badge-zulip]][yscope-community-zulip]

• Related PR: docs: Add Slack community invite badge to home page README. #1418
• Related comment: docs: Add Slack community invite badge to home page README. #1418 (comment)

Badge Details

Use the same badge configuration as in README.md:

• Badge markdown: [![Slack][badge-slack]][yscope-community-slack]
• Badge definition: [badge-slack]: https://img.shields.io/badge/Slack-yscope--community-1e724f?style=flat&logo=slack&logoColor=white&labelColor=4A154B
• Link definition: [yscope-community-slack]: https://communityinviter.com/apps/yscopecommunity/yscope-community

Requested by: @junhaoliao