✨ Support Python internal description on Pydantic model's docstring (#3032)

Co-authored-by: Sebastián Ramírez <tiangolo@gmail.com>

fastapi/utils.py

@@ -37,6 +37,8 @@ def get_model_definitions(
         )
         definitions.update(m_definitions)
         model_name = model_name_map[model]
+        if "description" in m_schema:
+            m_schema["description"] = m_schema["description"].split("\f")[0]
         definitions[model_name] = m_schema
     return definitions