include: Clean up SDL_AppResult documentation.

include/SDL3/SDL_init.h

@@ -73,13 +73,21 @@ typedef Uint32 SDL_InitFlags;
  * https://wiki.libsdl.org/SDL3/README/main-functions#main-callbacks-in-sdl3
  * for details.
  *
+ * Returning SDL_APP_SUCCESS or SDL_APP_FAILURE from SDL_AppInit, SDL_AppEvent, or SDL_AppIterate
+ * will terminate the program and report success/failure to the operating system. What that means
+ * is platform-dependent. On Unix, for example, on success, the process error code will be zero,
+ * and on failure it will be 1. This interface doesn't allow you to return specific exit codes,
+ * just whether there was an error generally or not.
+ *
+ * Returning SDL_APP_CONTINUE from these functions will let the app continue to run.
+ *
  * \since This enum is available since SDL 3.0.0.
  */
 typedef enum SDL_AppResult
 {
-    SDL_APP_CONTINUE,   /** Value that requests that the app continue from the main callbacks. If SDL_AppInit, SDL_AppEvent, or SDL_AppIterate returns this value, the program will continue to run. */
-    SDL_APP_SUCCESS,    /** Value that requests termination with success from the main callbacks. If SDL_AppInit, SDL_AppEvent, or SDL_AppIterate returns this value, the program will terminate and report success to the operating system. What that success looks like is platform-dependent. On Unix, for example, the process error code will be zero. */
-    SDL_APP_FAILURE     /** Value that requests termination with error from the main callbacks. If SDL_AppInit, SDL_AppEvent, or SDL_AppIterate returns this value, the program will terminate and report failure to the operating system. What that failure looks like is platform-dependent. On Unix, for example, the process error code will be non-zero. */
+    SDL_APP_CONTINUE,   /** Value that requests that the app continue from the main callbacks. */
+    SDL_APP_SUCCESS,    /** Value that requests termination with success from the main callbacks. */
+    SDL_APP_FAILURE     /** Value that requests termination with error from the main callbacks. */
 } SDL_AppResult;
 
 typedef SDL_AppResult (SDLCALL *SDL_AppInit_func)(void **appstate, int argc, char *argv[]);