[Core] Change OLED task function to be boolean (#14864)

* [Core] Add kb level callbacks to OLED driver

* Update keyboards and keymaps

* Update docs

* Update userspace configs

* Add fix for my keymap ...

* update lefty

keyboards/ein_60/keymaps/default/keymap.c

@@ -167,11 +167,12 @@ static void render_status(void) {
     oled_set_cursor(1,2);
 }
 
-void oled_task_user(void) {
+bool oled_task_user(void) {
 
     render_status();
     oled_write_ln_P(PSTR(""), false);
     render_ein60_logo();
+    return false;
 }
 #endif