rebuild notes plugin when html changes

gulpfile.js

@@ -298,7 +298,7 @@ gulp.task('serve', () => {
 
     gulp.watch(['js/**'], gulp.series('js', 'reload', 'eslint'))
 
-    gulp.watch(['plugin/**/plugin.js'], gulp.series('plugins', 'reload'))
+    gulp.watch(['plugin/**/plugin.js', 'plugin/**/*.html'], gulp.series('plugins', 'reload'))
 
     gulp.watch([
         'css/theme/source/*.{sass,scss}',

plugin/notes/speaker-view.html

@@ -368,7 +368,8 @@
 
 				window.addEventListener( 'message', function( event ) {
 
-					if (window.location.origin !== event.origin){
+					// Ignore post messages from other origins to prevent XSS
+					if( window.location.origin !== event.origin ){
 						return;
 					}