adds allowed_origins to collab OPS documentation

src/content/collaboration/operations/configure.mdx

@@ -30,6 +30,7 @@ Several `key` settings can be adjusted dynamically:
 - `default_auto_versioning`: Turn auto versioning on or off by default (1 for enabled, 0 for off).
 - `default_auto_versioning_interval`: Default versioning interval (default is 30 seconds)
 - `webhook_log_errors_only`: turn off webhook success logs (from v3.9.8)
+- `allowed_origins`: If set, this will validate `Origin` headers from clients to match with one of the provided values (comma separated). Example value: `https://test.tiptap.dev,https://prod.tiptap.dev` ; if not set, origin header validation is turned off. (from 3.11.0)
 
 ## Managing Settings via API