refactor(infra): directory structure (#4615)

packages/frontend/core/src/utils/create-emotion-cache.ts

@@ -0,0 +1,15 @@
+import { isBrowser } from '@affine/env/constant';
+import createCache from '@emotion/cache';
+
+export default function createEmotionCache() {
+  let insertionPoint;
+
+  if (isBrowser) {
+    const emotionInsertionPoint = document.querySelector<HTMLMetaElement>(
+      'meta[name="emotion-insertion-point"]'
+    );
+    insertionPoint = emotionInsertionPoint ?? undefined;
+  }
+
+  return createCache({ key: 'affine', insertionPoint });
+}