Doc search only returns API reference matches

[gonzalocasas]

The search function of the docs is only showing matches in the API reference, and all the rest of the docs are ignored.

To Reproduce Steps to reproduce the behavior:

1. Open docs, and search for anything present in the non API reference, eg. "Getting started"
2. Zero results

For example: try this search

Expected behavior At least one match should be found.

Additional context This does not happen with readthedocs search, so I am assuming it's not a sphinx issue but something we do in the preprocessing of search results. Considering the number of issues with had this preprocessing, should we just drop it?

[gonzalocasas]

/cc @yck011522