add connection modal

web/src/modals/useModalState.js

@@ -0,0 +1,8 @@
+import React from 'react';
+
+export default function useModalState() {
+  const [isOpen, setOpen] = React.useState(false);
+  const close = () => setOpen(false);
+  const open = () => setOpen(true);
+  return { isOpen, open, close };
+}