Add a button to route the user to the login page

[Svenstar74]

User story

When you are not logged in and you go to the route "/conversations", you'll find a button at the bottom so that a user can register. On top of that, there should be a second button "Login", which would route the user to the login page.

Acceptance criteria

• Above the register button there's a new button that says 'Login'.
• Pressing that button brings the user to the login page.