docsearch (algolia): better search (more granular)

[Horryportier]

While trying to use search bar I've noticed that I'm not redirected to place I wanted but to section which took me some time to realize that.
Example.
search: nvim_create_buf
redirected: https://neovim.io/doc/user/api.html#api-command

Would be nice if i was immediately redirected to nvim_create_buf section.

[justinmk]

A quick improvement here would be to render the help-tag-right elements as <h4> (or h3/h5/etc).