refactor style loading for the Editor

packages/core/src/utils/createStyleTag.ts

@@ -0,0 +1,8 @@
+export default function createStyleTag(style: string): HTMLStyleElement {
+  const styleNode = document.createElement('style')
+
+  styleNode.innerHTML = style
+  document.getElementsByTagName('head')[0].appendChild(styleNode)
+
+  return styleNode
+}