Add Try Python Den button to Play page

[faucomte97]

Task Description

Hurray, the Python Den is here.

We need to add a button the Play page to direct users to the Python Den, like we do with Rapid Router.

Design:

Please note: We're switching the wording from "Play" to "Try".

Acceptance Criteria

• Add new button next to existing "Play Rapid Router" button
• The button should redirect to the Python Den page (same functionality as the existing "Play Python Den" button at the bottom of the page)
• Update the wording of all buttons on the page from "Play" to "Try"

Good Places to Start

Play page template: https://github.com/ocadotechnology/codeforlife-portal/blob/master/portal/templates/portal/play.html