gi-docgen already puts types on most documented things. Thus most of this is replacing the linking with normal text.
But otherwise things are linked into GLib, internally, etc.


Improve documentation of manager

  For parameters, dropped the types because gi-docgen shows them automatically. It also shows transfer full, etc., so don't write extra notes about referencing and freeing.

  The types are not correctly shown on signals, which are kept in docs.

  Also, break up some paragraphs so that the details are not shown in the summaries on the overview page for the Manager.
Clean up loader docs

  Most of the links are not needed, so this just makes them normal text.
Fix doc cross-references in plugin info

  Like before, most of this is actually removing extra cross-references, but there are still one or two left.
Clean up cross references in plugin interface
Fix cross-referencing in top-level functions

Compiled and looked at docs in the browser.