fixed two bugs for audio only files: sometimes downloads failed as extensions were improperly removed and readded, removing a single character from the filename.
Fixed another extension-related bug where metadata from deleted audio files persisted
<p><ng-containeri18n="Bookmarklet instructions">Drag the link below to your bookmarks, and you're good to go! Just navigate to the YouTube video you'd like to download, and click the bookmark.</ng-container></p>
<mat-checkbox(change)="bookmarkletAudioOnlyChanged($event)"><ng-containeri18n="Generate audio only bookmarklet checkbox">Generate 'audio only' bookmarklet</ng-container></mat-checkbox>