wikiheaders: bridge wiki Category docs to the headers!

Did an initial cleanup on the headers and wrote a few pieces of documentation,
but this needs more work to fill out the documentation.

include/SDL3/SDL_hints.h

@@ -20,20 +20,20 @@
 */
 
 /**
- *  \file SDL_hints.h
+ * # CategoryHints
  *
- *  Official documentation for SDL configuration variables
+ * Official documentation for SDL configuration variables
  *
- *  This file contains functions to set and get configuration hints,
- *  as well as listing each of them alphabetically.
+ * This file contains functions to set and get configuration hints, as well as
+ * listing each of them alphabetically.
  *
- *  The convention for naming hints is SDL_HINT_X, where "SDL_X" is
- *  the environment variable that can be used to override the default.
+ * The convention for naming hints is SDL_HINT_X, where "SDL_X" is the
+ * environment variable that can be used to override the default.
  *
- *  In general these hints are just that - they may or may not be
- *  supported or applicable on any given platform, but they provide
- *  a way for an application or user to give the library a hint as
- *  to how they would like the library to work.
+ * In general these hints are just that - they may or may not be supported or
+ * applicable on any given platform, but they provide a way for an application
+ * or user to give the library a hint as to how they would like the library to
+ * work.
  */
 
 #ifndef SDL_hints_h_