Merge pull request EESSI#634 from EESSI/fix-slack-link

Add a single source for Slack invite URL in mkdocs.yml

Author: trz42

docs/contact.md

@@ -5,7 +5,7 @@ For more information:
 * Visit our [website](https://www.eessi.io)
 * Consult our [documentation](https://eessi.github.io/docs)
 * Ask for help at our [support portal](support.md)
-* Join our [Slack channel](https://join.slack.com/t/eessi-hpc/shared_invite/zt-2wg10p26d-m_CnRB89xQq3zk9qxf1k3g)
+* Join our [Slack channel]({{ config.extra.slack_invite_url }})
 * Reach out to one of the [project partners](partners.md)
 * Check out our GitHub [repositories](https://github.com/EESSI)
 * Follow us on [Twitter](https://twitter.com/eessi_hpc)

docs/training-events/2025/happy-hours-sessions.md

@@ -27,7 +27,7 @@ All sessions will be recorded. Recordings, slides, and materials used will be ma
 - Online sessions (via Zoom)
 - Mix of presentation & hands-on demos: ~15min of content, ~30min for Q&A
 
-If you haven't joined the EESSI Slack yet, [click here to join](https://join.slack.com/t/eessi-hpc/shared_invite/zt-1wqy0t8g6-PZJTg3Hjjm5Fm3XEOkzECg)
+If you haven't joined the EESSI Slack yet, [click here to join]({{ config.extra.slack_invite_url }})
 
 ---
 
@@ -108,4 +108,3 @@ See the full Recordings, slides, and materials here: [Previous Sessions & Videos
 - 25 August 2025 - [Accessing EESSI using container script](https://www.youtube.com/watch?v=MAgWwj27i9U)
 
 - 18 August 2025 - [Installing and configuring CernVM-FS](https://youtu.be/MLeSbMOnbs8)
-

mkdocs.yml

@@ -178,6 +178,7 @@ extra:
       link: https://twitter.com/eessi_hpc
   # this gets auto-updated via update_generated_time.sh script run in update_available_software.yml action
   generated_time: "Fri, 28 Nov 2025 at 01:53:03 UTC"
+  slack_invite_url: "https://join.slack.com/t/eessi-hpc/shared_invite/zt-1wqy0t8g6-PZJTg3Hjjm5Fm3XEOkzECg"
 extra_javascript:
   # mermaid diagram
   - https://cdn.jsdelivr.net/npm/mermaid@10/dist/mermaid.esm.min.mjs