New login screen (#1331)

* wip

* feat: first draft of auth.config

* chore: auth methodS

* chore: styling

* styling, styling, styling

* feat: Auth notices

* chore: Remove server-rendered pages, move shared/components -> components

* lint

* cleanup

* cleanup

* fix: Remove unused component

* fix: Ensure env variables in prod too

* style tweaks

* fix: Entering SSO email into login form fails
fix: Tweak language around guest signin

app/components/Branding.js

@@ -0,0 +1,41 @@
+// @flow
+import * as React from "react";
+import styled from "styled-components";
+import OutlineLogo from "./OutlineLogo";
+
+type Props = {
+  href?: string,
+};
+
+function Branding({ href = process.env.URL }: Props) {
+  return (
+    <Link href={href}>
+      <OutlineLogo size={16} />&nbsp;Outline
+    </Link>
+  );
+}
+
+const Link = styled.a`
+  position: fixed;
+  bottom: 0;
+  left: 0;
+
+  font-weight: 600;
+  font-size: 14px;
+  text-decoration: none;
+  border-top-right-radius: 2px;
+  color: ${props => props.theme.text};
+  display: flex;
+  align-items: center;
+  padding: 16px;
+
+  svg {
+    fill: ${props => props.theme.text};
+  }
+
+  &:hover {
+    background: ${props => props.theme.sidebarBackground};
+  }
+`;
+
+export default Branding;