message: Add `@internal` as a synonym for `@hidden`
  Closes
diff: @@ -110,7 +110,10 @@ export class CommentPlugin extends ConverterComponent {
  CommentPlugin.removeTags(comment, 'event');
  }
  - if (comment.hasTag('hidden') || comment.hasTag('ignore')) {
  + if (comment.hasTag('hidden')
  + || comment.hasTag('ignore')
  + || (comment.hasTag('internal') && this.application.options.getCompilerOptions().stripInternal)
  + ) {
  if (!this.hidden) {
  this.hidden = [];
  }
  