Cleanup webpack example configs (#606)

* Remove Buffer/process plugins

* Adjust

* Cleanup README

packages/example-react/webpack.config.cjs

@@ -3,7 +3,6 @@
 
 const path = require('path');
 const { WebpackPluginServe } = require('webpack-plugin-serve');
-const webpack = require('webpack');
 
 module.exports = {
   context: __dirname,
@@ -37,12 +36,6 @@ module.exports = {
       port: 8080,
       progress: false, // since we have hmr off, disable
       static: __dirname
-    }),
-    new webpack.ProvidePlugin({
-      Buffer: ['buffer', 'Buffer']
-    }),
-    new webpack.ProvidePlugin({
-      process: 'process/browser'
     })
   ],
   resolve: {
@@ -51,14 +44,11 @@ module.exports = {
       '@polkadot/ui-keyring': path.resolve(__dirname, '../ui-keyring/build'),
       '@polkadot/ui-settings': path.resolve(__dirname, '../ui-settings/build'),
       '@polkadot/ui-shared': path.resolve(__dirname, '../ui-shared/build'),
-      'process/browser': require.resolve('process/browser'),
       'react/jsx-runtime': require.resolve('react/jsx-runtime')
     },
     extensions: ['.js', '.ts', '.tsx'],
-    fallback: {
-      buffer: require.resolve('buffer'),
-      stream: require.resolve('stream-browserify')
-    }
+    fallback: {}
   },
+  target: 'web',
   watch: true
 };