Cleanup webpack example configs (#606)

* Remove Buffer/process plugins

* Adjust

* Cleanup README

packages/react-identicon/src/Demo.tsx

@@ -1,54 +0,0 @@
-// Copyright 2017-2022 @polkadot/react-identicon authors & contributors
-// SPDX-License-Identifier: Apache-2.0
-
-import React from 'react';
-import ReactDOM from 'react-dom';
-
-import { encodeAddress, randomAsU8a } from '@polkadot/util-crypto';
-
-import { Identicon } from '.';
-
-const THEMES = ['beachball', 'polkadot', 'substrate'];
-
-export default class Demo extends React.PureComponent {
-  public override render (): React.ReactNode {
-    const identities: string[] = [];
-
-    while (identities.length !== 50) {
-      identities.push(
-        encodeAddress(randomAsU8a(32))
-      );
-    }
-
-    return (
-      <div>
-        <div>
-          {identities.map((value, index): React.ReactNode => (
-            <Identicon
-              key={value.toString()}
-              theme={THEMES[index % THEMES.length] as 'empty'}
-              value={value}
-            />
-          ))}
-        </div>
-        <div>
-          {THEMES.map((theme): React.ReactNode => (
-            <Identicon
-              key={theme}
-              theme={theme as 'empty'}
-              value='5GrwvaEF5zXb26Fz9rcQpDWS57CtERHpNehXCPcNoHGKutQY'
-            />
-          ))}
-        </div>
-      </div>
-    );
-  }
-}
-
-const rootElement = document.getElementById('demo');
-
-if (!rootElement) {
-  throw new Error('Unable to find element with id \'demo\'');
-}
-
-ReactDOM.render(<Demo />, rootElement);