fix: expose accordion contents and add clear insert actions (1.8.3)

public/assets/preview.css

@@ -20,4 +20,6 @@
 .editor-container:hover:not(.editor-selected),.editor-dragging .editor-container{outline:1px dashed #6b927a;outline-offset:-1px}
 .editor-container.editor-insert-target{outline:3px solid #b55b12!important;outline-offset:-3px}
 .editor-dragging .editor-empty{background:#e6f1e9;border-color:#467858}
+.editor-add-content{min-height:0;margin-top:12px;padding:10px;border-width:1px;background:#f3f8f4}
+.block-accordion.editor-container>.editor-add-content{margin-top:16px}
 @media(max-width:650px){.editor-empty{padding:16px 10px}.editor-empty button{min-height:44px}}