Fix README: list_table_relationships includes ManyToOne (confirmed Dataverse API)

Dataverse Web API supports EntityDefinitions({id})/ManyToOneRelationships
as a standard metadata endpoint. ManyToOne is the outgoing lookup
perspective (child -> parent), complementing OneToMany (parent -> child).

- README: 'one-to-many + many-to-many' -> 'one-to-many + many-to-one + many-to-many'
- _relationships.py docstring updated to match
- copilot-instructions.md: added SKILL.md reference to governance list

770 unit tests passing.

Author: Saurabh Badenkal

README.md

@@ -559,7 +559,7 @@ rels = client.tables.list_relationships()
 for rel in rels:
     print(f"{rel['SchemaName']} ({rel.get('@odata.type')})")
 
-# List relationships for a specific table (one-to-many + many-to-many)
+# List relationships for a specific table (one-to-many + many-to-one + many-to-many)
 account_rels = client.tables.list_table_relationships("account")
 for rel in account_rels:
     print(f"{rel['SchemaName']} -> {rel.get('@odata.type')}")

src/PowerPlatform/Dataverse/data/_relationships.py

@@ -198,8 +198,8 @@ def _list_table_relationships(
             ``$select``.  Values are passed as-is (PascalCase).
         :type select: ``list[str]`` or ``None``
 
-        :return: Combined list of one-to-many and many-to-many relationship
-            metadata dictionaries (may be empty).
+        :return: Combined list of one-to-many, many-to-one, and many-to-many
+            relationship metadata dictionaries (may be empty).
         :rtype: ``list[dict[str, Any]]``
 
         :raises MetadataError: If the table is not found.