* Updated Metadata page: add common and additional metadata fields by
document types and connectors
* Updated specific installation extra by document types and connectors
* Added embedding brick page in Sphinx TOC
* Fixed Sphinx warnings in new pages
### Description
This PR is two-fold:
**Embeddings:**
* Embeddings incorporated into the sharepoint source connector, which
will now call out to OpenAI and create embeddings if the flag is passed
in and the api key provided.
**Writing vector content (embeddings) to Azure cognitive search index:**
* The schema for the index expected to exist in Azure has been updated
to include the vector field type and a test script has been added to
test the new content being produced from the Sharepoint connector to
push the embedding content.
Some important notes about other changes in here:
* The embedding code had to be updated to patch the `to_dict` method on
elements to add `embeddings` to the dict output if that was added. While
the code originally added the embedding content, when `to_dict` was
called to save the content as json, this was lost.
### Description
New [Azure Cognitive
Search](https://azure.microsoft.com/en-us/products/ai-services/cognitive-search)
destination connector added. Writes each json element from the created
json files via partition and writes that content to an index.
**Bonus bug fix:** Due to a recent change where the default version of
python used in the repo was bumped to `3.10` from `3.8`, this means
running `pip-compile` now runs it against that version rather than the
lowest we support which is still `3.8`. This breaks the setup for those
lower versions because some of the versions pulled in by `pip-compile`
exist for `3.10` but not `3.8`. `pip-compile` was updates to run as a
script that checks the version of python being used first, which helps
guarantee that all dependencies meet the minimum python version
requirement.
Closes out https://github.com/Unstructured-IO/unstructured/issues/1466
