add login/sign-up page with dark/light mode

node_modules/eslint-plugin-jsx-a11y/__mocks__/IdentifierMock.js

@@ -0,0 +1,15 @@
+/**
+ * @flow
+ */
+
+export type IdentifierMockType = {|
+  type: 'Identifier',
+  name: string,
+|};
+
+export default function IdentifierMock(ident: string): IdentifierMockType {
+  return {
+    type: 'Identifier',
+    name: ident,
+  };
+}