Add authentication

apps/builder/pages/signin.tsx

@@ -0,0 +1,16 @@
+import { AuthSwitcher } from 'components/auth/AuthSwitcher'
+import { SignInForm } from 'components/auth/SignInForm'
+import { Heading, VStack } from '@chakra-ui/react'
+import React from 'react'
+
+const SignInPage = () => {
+  return (
+    <VStack spacing={4} h="100vh" justifyContent="center">
+      <Heading>Sign in</Heading>
+      <AuthSwitcher type="signin" />
+      <SignInForm />
+    </VStack>
+  )
+}
+
+export default SignInPage