docs: docstrings langchain_community update (#14889)

Addded missed docstrings. Fixed inconsistency in docstrings.

**Note** CC @efriis 
There were PR errors on
`langchain_experimental/prompt_injection_identifier/hugging_face_identifier.py`
But, I didn't touch this file in this PR! Can it be some cache problems?
I fixed this error.

libs/community/langchain_community/llms/xinference.py

@@ -9,7 +9,8 @@ if TYPE_CHECKING:
 
 
 class Xinference(LLM):
-    """Wrapper for accessing Xinference's large-scale model inference service.
+    """`Xinference` large-scale model inference service.
+
     To use, you should have the xinference library installed:
 
     .. code-block:: bash