deprecate community docugami loader (#19230)

Thank you for contributing to LangChain!

- [x] **PR title**: "community: deprecate DocugamiLoader"

- [x] **PR message**: Deprecate the langchain_community and use the
docugami_langchain DocugamiLoader

---------

Co-authored-by: Kenzie Mihardja <kenzie28@cs.washington.edu>

libs/community/langchain_community/document_loaders/docugami.py

@@ -6,6 +6,7 @@ from pathlib import Path
 from typing import Any, Dict, List, Mapping, Optional, Sequence, Union
 
 import requests
+from langchain_core._api.deprecation import deprecated
 from langchain_core.documents import Document
 from langchain_core.pydantic_v1 import BaseModel, root_validator
 
@@ -26,6 +27,11 @@ DEFAULT_API_ENDPOINT = "https://api.docugami.com/v1preview1"
 logger = logging.getLogger(__name__)
 
 
+@deprecated(
+    since="0.0.24",
+    removal="0.2.0",
+    alternative_import="docugami_langchain.DocugamiLoader",
+)
 class DocugamiLoader(BaseLoader, BaseModel):
     """Load from `Docugami`.