wikiheaders: Automatically categorize API symbols by subsystem.

.wikiheaders-options

@@ -17,3 +17,7 @@ warn_about_missing = 0
 wikipreamble = (This is the documentation for SDL3, which is under heavy development and the API is changing! [SDL2](https://wiki.libsdl.org/SDL2/) is the current stable version!)
 wikiheaderfiletext = Defined in [<SDL3/%fname%>](https://github.com/libsdl-org/SDL/blob/main/include/SDL3/%fname%)
 manpageheaderfiletext = Defined in SDL3/%fname%
+
+# All SDL_test_* headers become "Test" categories, everything else just converts like SDL_audio.h -> Audio
+# A handful of others we fix up in the header itself with /* WIKI CATEGORY: x */ comments.
+headercategoryeval = s/\ASDL_test_.*?\.h\Z/Test/; s/\ASDL_?(.*?)\.h\Z/$1/; ucfirst();