fix className for bootstrap 5

packages/editor/src/components/playground/Playground.tsx

@@ -22,11 +22,11 @@ export const Playground = (): JSX.Element => {
       <div className="flex-grow-1 d-flex flex-column justify-content-center align-items-center bg-dark" style={{ minHeight: '83px' }}>
         <div className="text-white">GrowiSubnavigation</div>
       </div>
-      <div className="flex-grow-1 d-flex overflow-auto">
+      <div className="flex-grow-1 d-flex overflow-y-auto">
         <div className="flex-grow-1 d-flex flex-column">
           <CodeMirrorEditorContainer ref={containerRef} />
         </div>
-        <div className="flex-grow-1 d-flex flex-column justify-content-center align-items-center bg-light border-left border-dark-subtle">
+        <div className="flex-grow-1 d-flex flex-column justify-content-center align-items-center bg-light border-start border-dark-subtle">
           <p>PREVIEW</p>
         </div>
       </div>