chore: move frontend files

frontend/env.config.d.ts

@@ -0,0 +1,9 @@
+declare module 'postcss-easings' {
+  import postcssEasings from 'postcss-easings'
+  export default postcssEasings
+}
+
+declare module 'postcss-easing-gradients' {
+  import postcssEasingGradients from 'postcss-easing-gradients'
+  export default postcssEasingGradients
+}