[WIP] Add welcome message to copilot-cli discussions

[Claude]

Thanks for asking me to work on this. I will get started on it and keep this PR's description up to date as I form a plan and make progress.

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This section details on the original issue you should resolve

<issue_title>Welcome to copilot-cli Discussions!</issue_title>
<issue_description>

Discussed in #1

^{Originally posted by edelbandsway May 11, 2026}

👋 Welcome!

We’re using Discussions as a place to connect with other members of our community. We hope that you:

• Ask questions you’re wondering about.
• Share ideas.
• Engage with other community members.
• Welcome others and are open-minded. Remember that this is a community we
  build together 💪.

To get started, comment below with an introduction of yourself and tell us about what you do with this community.

Comments on the Issue (you are @claude[agent] in this section)