Sync SDL2 wiki -> header

include/SDL_events.h

@@ -637,6 +637,14 @@ typedef struct SDL_SysWMEvent
 
 /**
  * General event structure
+ *
+ * The SDL_Event structure is the core of all event handling in SDL. SDL_Event
+ * is a union of all event structures used in SDL. Using it is a simple matter
+ * of knowing which event type corresponds to which union member. The table
+ * below lists these relationships.
+ *
+ * The SDL_Event structure has two uses: * Reading events from the event queue
+ * * Placing events on the event queue
  */
 typedef union SDL_Event
 {