Move release notes for older releases to a separate page

[GlitchBuddy]

The releases page at https://grapheneos.org/releases currently contains release notes for every version released since the project's launch back in 2019. This results in an extremely long and cluttered webpage that is hard to navigate.

I believe that the main releases page should only contain the release notes for the past 1-3 versions of GrapheneOS, and the changelogs for all older versions should be moved to a separate page. This would help maintain access to the older release notes for people wanting to review the changes, as well as greatly streamline the main releases page to focus more on the current releases and their download links.

[thestinger]

The project was launched in 2014, not 2019. There are older release notes at https://grapheneos.org/history/legacy-changelog. We could move more of them there.