Add changelog to About page

[KCarlile]

Background

The changelog should be part of the about page, including the current version, so users can see when updates happened.

Acceptance Criteria

• Changelog with dates and versions are included on the About page
• Changes should be automatically pulled in so the About page doesn't have to be manually updated

Approach

• Create a PHP file to parse the changelog and render it as HTML
• Include that PHP file on the About page

Notes

N/A