updated react app and API backend

1. Added API backend for settings
2. Added React components for the settings page
3. Added JS lint using @wordpress/scripts
4. Lint fixes for PHP

vite.config.js

@@ -1,16 +1,16 @@
 import { defineConfig } from 'vite';
 import react from '@vitejs/plugin-react';
 
-export default defineConfig({
-  plugins: [react()],
-  build: {
-    outDir: 'build',
-    emptyOutDir: true,
-    rollupOptions: {
-      input: 'src/App.jsx',
-      output: {
-        entryFileNames: 'index.js'
-      }
-    }
-  }
-});
+export default defineConfig( {
+	plugins: [ react() ],
+	build: {
+		outDir: 'build',
+		emptyOutDir: true,
+		rollupOptions: {
+			input: 'src/App.jsx',
+			output: {
+				entryFileNames: 'index.js',
+			},
+		},
+	},
+} );