Apply `/transparency` layout to `/about`, `/join-us`, and `/contact`

[marco-souza]

Context

Currently, the /transparency page is the most complete one! It has different sections, accurate information, and an engaging text - besides being gorgeous!

We need to use it as an inspiration for all the other pages as well!

Requirements

• Make the other pages as gorgeous as /transparency
• Components: create components as needed, to avoid duplicating shared code
• Create e2e tests for the updated pages