feat(themeManager): Exposed method to enable automatic global theme change.

ts/domtools.classes.thememanager.ts

@@ -21,7 +21,7 @@ export class ThemeManager {
     this.updateAllConnectedElements();
   }
 
-  private async setGlobalStylesOnPurpose() {
+  public async enableAutomaticGlobalThemeChange() {
     if (document.body && document.body.style) {
       document.body.style.background = this.goBrightBoolean ? '#fff' : '#000';
     }