docs: fix legend formatting in deployment comparison table

Agent-Logs-Url: https://github.com/nextcloud/documentation/sessions/5659f8f5-62ae-4f33-b3f1-d1a8bde86b1f

Co-authored-by: szaimen <42591237+szaimen@users.noreply.github.com>

Author: Copilot

admin_manual/installation/deployment_comparison.rst

@@ -202,9 +202,9 @@ you choose the one that best suits your needs.
      - ✅
      - ❌
 
-✅ = included / supported out of the box |
-⚠️ = possible but requires manual steps or has caveats |
-❌ = not supported / not included
+* ✅ = included / supported out of the box
+* ⚠️ = possible but requires manual steps or has caveats
+* ❌ = not supported / not included
 
 .. note::