### Summary
Adds a new document loader for processing e-publications. Works with
`unstructured>=0.5.4`. You need to have
[`pandoc`](https://pandoc.org/installing.html) installed for this loader
to work.
### Testing
```python
from langchain.document_loaders import UnstructuredEPubLoader
loader = UnstructuredEPubLoader("winter-sports.epub", mode="elements")
data = loader.load()
data[0]
```
- Current docs are pointing to the wrong module, fixed
- Added some explanation on how to find the necessary parameters
- Added chat-based codegen example w/ retrievers
Picture of the new page:
![Screenshot 2023-03-29 at 20-11-29 Figma — 🦜🔗 LangChain 0 0
126](https://user-images.githubusercontent.com/2172753/228719338-c7ec5b11-01c2-4378-952e-38bc809f217b.png)
Please let me know if you'd like any tweaks! I wasn't sure if the
example was too heavy for the page or not but decided "hey, I probably
would want to see it" and so included it.
Co-authored-by: maxtheman <max@maxs-mbp.lan>
This PR adds Notion DB loader for langchain.
It reads content from pages within a Notion Database. It uses the Notion
API to query the database and read the pages. It also reads the metadata
from the pages and stores it in the Document object.