add missing signup file

pages/signup.js

@@ -0,0 +1,51 @@
+import { providers, getSession } from 'next-auth/client'
+import Link from 'next/link'
+import Login from '../components/login'
+
+export async function getServerSideProps ({ req, res, query: { callbackUrl, error = null } }) {
+  const session = await getSession({ req })
+
+  if (session && res && callbackUrl) {
+    res.writeHead(302, {
+      Location: callbackUrl
+    })
+    res.end()
+    return { props: {} }
+  }
+
+  return {
+    props: {
+      providers: await providers({ req, res }),
+      callbackUrl,
+      error
+    }
+  }
+}
+
+function SignUpHeader () {
+  return (
+    <>
+      <h3 className='w-100 pb-2'>
+        Sign up
+      </h3>
+      <div className='font-weight-bold text-muted pb-4'>Join 9000+ bitcoiners and start stacking sats today</div>
+    </>
+  )
+}
+
+function SignUpFooter ({ callbackUrl }) {
+  return (
+    <small className='font-weight-bold text-muted pt-4'>Already have an account? <Link href={{ pathname: '/login', query: { callbackUrl } }}>login</Link></small>
+  )
+}
+
+export default function SignUp ({ ...props }) {
+  return (
+    <Login
+      Header={() => <SignUpHeader />}
+      Footer={() => <SignUpFooter callbackUrl={props.callbackUrl} />}
+      text='Sign up'
+      {...props}
+    />
+  )
+}