Sync SDL3 wiki -> header

[ci skip]

Author: SDLWikiBot

docs/README-platforms.md

@@ -21,7 +21,6 @@ SDL3 has been known to work on the following platforms at some point:
 - [PlayStation 5](README-ps5.md) (Separate NDA-only fork)
 - [PlayStation Portable](README-psp.md) (Homebrew)
 - [PlayStation Vita](README-vita.md) (Homebrew)
-- QNX
 - [RISC OS](README-riscos.md)
 - [SteamOS](README-steamos.md)
 - [tvOS](README-ios.md)
@@ -40,6 +39,7 @@ If your favorite system is listed below, we aren't working on it. However, if yo
 
 All of these still work with [SDL2](/SDL2), which is an incompatible API, but an option if you need to support these platforms still.
 
+- QNX
 - Google Stadia
 - NaCL
 - OS/2