Improve indexing of content

[RobPasMue]

Currently the static search is not working that great whenever our API reference is based on autoapi.

See example:

I know for a fact that there is a method called "create_design", that is available at https://geometry.docs.pyansys.com/version/stable/api/ansys/geometry/core/modeler/Modeler.html#Modeler.create_design

However, the static search is not indexing properly subsections inside my API page - only summary, description and some other elements are being indexed, making the search completely broken. We should fix this because currently the static search is not usable for our API reference.

Pinging @ansys/pyansys-core for visibility