community[minor]: added new document loaders based on dedoc library (#…

…24303)

### Description
This pull request added new document loaders to load documents of
various formats using [Dedoc](https://github.com/ispras/dedoc):
  - `DedocFileLoader` (determine file types automatically and parse)
  - `DedocPDFLoader` (for `PDF` and images parsing)
- `DedocAPIFileLoader` (determine file types automatically and parse
using Dedoc API without library installation)

[Dedoc](https://dedoc.readthedocs.io) is an open-source library/service
that extracts texts, tables, attached files and document structure
(e.g., titles, list items, etc.) from files of various formats. The
library is actively developed and maintained by a group of developers.

`Dedoc` supports `DOCX`, `XLSX`, `PPTX`, `EML`, `HTML`, `PDF`, images
and more.
Full list of supported formats can be found
[here](https://dedoc.readthedocs.io/en/latest/#id1).
For `PDF` documents, `Dedoc` allows to determine textual layer
correctness and split the document into paragraphs.


### Issue
This pull request extends variety of document loaders supported by
`langchain_community` allowing users to choose the most suitable option
for raw documents parsing.

### Dependencies
The PR added a new (optional) dependency `dedoc>=2.2.5` ([library
documentation](https://dedoc.readthedocs.io)) to the
`extended_testing_deps.txt`

### Twitter handle
None

### Add tests and docs
1. Test for the integration:
`libs/community/tests/integration_tests/document_loaders/test_dedoc.py`
2. Example notebook:
`docs/docs/integrations/document_loaders/dedoc.ipynb`
3. Information about the library:
`docs/docs/integrations/providers/dedoc.mdx`

### Lint and test

Done locally:

  - `make format`
  - `make lint`
  - `make integration_tests`
  - `make docs_build` (from the project root)

---------

Co-authored-by: Nasty <[email protected]>

docs/docs/integrations/providers/dedoc.mdx

@@ -0,0 +1,56 @@
+# Dedoc
+
+>[Dedoc](https://dedoc.readthedocs.io) is an [open-source](https://github.com/ispras/dedoc)
+library/service that extracts texts, tables, attached files and document structure
+(e.g., titles, list items, etc.) from files of various formats.
+
+`Dedoc` supports `DOCX`, `XLSX`, `PPTX`, `EML`, `HTML`, `PDF`, images and more.
+Full list of supported formats can be found [here](https://dedoc.readthedocs.io/en/latest/#id1).
+
+## Installation and Setup
+
+### Dedoc library
+
+You can install `Dedoc` using `pip`.
+In this case, you will need to install dependencies,
+please go [here](https://dedoc.readthedocs.io/en/latest/getting_started/installation.html)
+to get more information.
+
+```bash
+pip install dedoc
+```
+
+### Dedoc API
+
+If you are going to use `Dedoc` API, you don't need to install `dedoc` library.
+In this case, you should run the `Dedoc` service, e.g. `Docker` container (please see
+[the documentation](https://dedoc.readthedocs.io/en/latest/getting_started/installation.html#install-and-run-dedoc-using-docker)
+for more details):
+
+```bash
+docker pull dedocproject/dedoc
+docker run -p 1231:1231
+```
+
+## Document Loader
+
+* For handling files of any formats (supported by `Dedoc`), you can use `DedocFileLoader`:
+
+    ```python
+    from langchain_community.document_loaders import DedocFileLoader
+    ```
+
+* For handling PDF files (with or without a textual layer), you can use `DedocPDFLoader`:
+
+    ```python
+    from langchain_community.document_loaders import DedocPDFLoader
+    ```
+
+* For handling files of any formats without library installation,
+you can use `Dedoc API` with `DedocAPIFileLoader`:
+
+    ```python
+    from langchain_community.document_loaders import DedocAPIFileLoader
+    ```
+
+Please see a [usage example](/docs/integrations/document_loaders/dedoc) for more details.

libs/community/extended_testing_deps.txt

@@ -16,6 +16,7 @@ cloudpickle>=2.0.0
 cohere>=4,<6
 databricks-vectorsearch>=0.21,<0.22
 datasets>=2.15.0,<3
+dedoc>=2.2.6,<3
 dgml-utils>=0.3.0,<0.4
 elasticsearch>=8.12.0,<9
 esprima>=4.0.1,<5

libs/community/langchain_community/document_loaders/__init__.py

@@ -142,6 +142,10 @@
     from langchain_community.document_loaders.dataframe import (
         DataFrameLoader,
     )
+    from langchain_community.document_loaders.dedoc import (
+        DedocAPIFileLoader,
+        DedocFileLoader,
+    )
     from langchain_community.document_loaders.diffbot import (
         DiffbotLoader,
     )
@@ -340,6 +344,7 @@
     )
     from langchain_community.document_loaders.pdf import (
         AmazonTextractPDFLoader,
+        DedocPDFLoader,
         MathpixPDFLoader,
         OnlinePDFLoader,
         PagedPDFSplitter,
@@ -570,6 +575,9 @@
     "CubeSemanticLoader": "langchain_community.document_loaders.cube_semantic",
     "DataFrameLoader": "langchain_community.document_loaders.dataframe",
     "DatadogLogsLoader": "langchain_community.document_loaders.datadog_logs",
+    "DedocAPIFileLoader": "langchain_community.document_loaders.dedoc",
+    "DedocFileLoader": "langchain_community.document_loaders.dedoc",
+    "DedocPDFLoader": "langchain_community.document_loaders.pdf",
     "DiffbotLoader": "langchain_community.document_loaders.diffbot",
     "DirectoryLoader": "langchain_community.document_loaders.directory",
     "DiscordChatLoader": "langchain_community.document_loaders.discord",
@@ -771,6 +779,9 @@ def __getattr__(name: str) -> Any:
     "CubeSemanticLoader",
     "DataFrameLoader",
     "DatadogLogsLoader",
+    "DedocAPIFileLoader",
+    "DedocFileLoader",
+    "DedocPDFLoader",
     "DiffbotLoader",
     "DirectoryLoader",
     "DiscordChatLoader",