Moved code into src folder. Added build for component library.

src/components/common/Favicon.js

@@ -0,0 +1,22 @@
+import styles from './Favicon.module.css';
+
+function getHostName(url) {
+  const match = url.match(/^(?:https?:\/\/)?(?:[^@\n]+@)?(?:www\.)?([^:/\n?=]+)/im);
+  return match && match.length > 1 ? match[1] : null;
+}
+
+export function Favicon({ domain, ...props }) {
+  const hostName = domain ? getHostName(domain) : null;
+
+  return hostName ? (
+    <img
+      className={styles.favicon}
+      src={`https://icons.duckduckgo.com/ip3/${hostName}.ico`}
+      height="16"
+      alt=""
+      {...props}
+    />
+  ) : null;
+}
+
+export default Favicon;