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

src/components/hooks/useEscapeKey.js

@@ -0,0 +1,21 @@
+import { useEffect, useCallback } from 'react';
+
+export function useEscapeKey(handler) {
+  const escFunction = useCallback(event => {
+    if (event.keyCode === 27) {
+      handler(event);
+    }
+  }, []);
+
+  useEffect(() => {
+    document.addEventListener('keydown', escFunction, false);
+
+    return () => {
+      document.removeEventListener('keydown', escFunction, false);
+    };
+  }, [escFunction]);
+
+  return null;
+}
+
+export default useEscapeKey;