Add collaboration redirects (#43471)

Redirect:

https://zed.dev/docs/collaboration ->
https://zed.dev/docs/collaboration/overview
https://zed.dev/docs/channels ->
https://zed.dev/docs/collaboration/channels

Release Notes:

- N/A
2053fea0a7Joseph T. Lyons committed on 11/25/2025, 4:28:33 PM· committed by GitHubparent552bc02
1 file changedLine totals unavailable