### Summary
Closes#1007. Adds a deprecation warning for the `file_filename` kwarg
to `partition`, `partition_via_api`, and `partition_multiple_via_api`.
Also catches a warning in `ebooklib` that we do not want to emit in
`unstructured`.
### Testing
```python
from unstructured.partition.auto import partition
filename = "example-docs/winter-sports.epub"
# Should not emit a warning
with open(filename, "rb") as f:
elements = partition(file=f, metadata_filename="test.epub")
# Should be test.epub
elements[0].metadata.filename
# Should emit a warning
with open(filename, "rb") as f:
elements = partition(file=f, file_filename="test.epub")
# Should be test.epub
elements[0].metadata.filename
# Should raise an error
with open(filename, "rb") as f:
elements = partition(file=f, metadata_filename="test.epub", file_filename="test.epub")
```
Documentation Overhaul
- Added documentation hierarchy
- Added options for Bash vs Python for API & Upstream Connectors
- Added Introduction section (Overview, Key Concepts, Getting Started)
- Redid connectors section
- Installation is now broken up (needs further work)
