[Feature] Login & Signup Page

[ruichen199801]

1. Login & Signup static UI
   • Login Page: https://www.figma.com/file/0UttRN5k6xkWka4epW8wz4/Forx-News?node-id=19%3A84
   • Signup Page: https://www.figma.com/file/0UttRN5k6xkWka4epW8wz4/Forx-News?node-id=19%3A51
2. A user can sign up a new account, login into our website, and get redirected to the landing page.
3. A user can sign in using Google or Twitter, and get redirected to the landing page.