feat: missing type language (#989)

* feat: missing type language

* chore: case

---------

Co-authored-by: Willhoit <iowillhoit@users.noreply.github.com>

messages/sdr.md

@@ -170,4 +170,12 @@ A metadata type lookup for "%s" found the following close matches:
 
 Additional suggestions:
 Confirm the file name, extension, and directory names are correct. Validate against the registry at:
-https://github.com/forcedotcom/source-deploy-retrieve/blob/main/src/registry/metadataRegistry.json
+<https://github.com/forcedotcom/source-deploy-retrieve/blob/main/src/registry/metadataRegistry.json>
+
+If the type is not listed in the registry, check that it has Metadata API support via the Metadata Coverage Report:
+<https://developer.salesforce.com/docs/metadata-coverage>
+
+If the type is available via Metadata API but not in the registry
+
+- Open an issue <https://github.com/forcedotcom/cli/issues>
+- Add the type via PR. Instructions: <https://github.com/forcedotcom/source-deploy-retrieve/blob/main/contributing/metadata.md>