feat(theme): ✨ Add custom css settings

apps/builder/components/theme/CustomCssSettings/CustomCssSettings.tsx

@@ -0,0 +1,17 @@
+import { CodeEditor } from 'components/shared/CodeEditor'
+import React from 'react'
+
+type Props = {
+  customCss?: string
+  onCustomCssChange: (css: string) => void
+}
+
+export const CustomCssSettings = ({ customCss, onCustomCssChange }: Props) => {
+  return (
+    <CodeEditor
+      value={customCss ?? ''}
+      lang="css"
+      onChange={onCustomCssChange}
+    />
+  )
+}