Move ui-identicon -> react-identicon (#165)

* Move ui-identicon -> react-identicon

* ui-identicon import fix

* Update README package links

* Update doc sidebar links

* Adjust react-qr signatures, CHANGELOG

packages/react-identicon/src/Demo.tsx

@@ -0,0 +1,37 @@
+// Copyright 2017-2019 @polkadot/react-identicon authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+import React from 'react';
+import ReactDOM from 'react-dom';
+import { encodeAddress, randomAsU8a } from '@polkadot/util-crypto';
+
+import IdentityIcon from '.';
+
+export default class Demo extends React.PureComponent {
+  public render (): React.ReactNode {
+    const identities: string[] = [];
+
+    while (identities.length !== 50) {
+      identities.push(
+        encodeAddress(randomAsU8a(32))
+      );
+    }
+
+    return identities.map((value): React.ReactNode => (
+      <IdentityIcon
+        key={value.toString()}
+        theme='jdenticon'
+        value={value}
+      />
+    ));
+  }
+}
+
+const rootElement = document.getElementById('demo');
+
+if (!rootElement) {
+  throw new Error(`Unable to find element with id 'demo'`);
+}
+
+ReactDOM.render(<Demo />, rootElement);