This diff introduces the download page where a user can press the button of the platform they are using to download the app on to their device.
I based the UI off of this low fidelity prototype, but very open to feedback/changing any of the copy and/or UI
{F2125507}
Linear task: https://linear.app/comm/issue/ENG-8009/add-download-links-for-all-platforms-to-landing-page