For both of my startups, I created a shared folder where anyone can dump things with the specific purpose of, "If we get super big and world famous, this would be interesting early history".
Sadly we never got big or famous, but the idea was there! Most of what was in there were early pictures of the team at important events.
I did this at a recent startup where I was first engineering hire. It was our "Nostalgia" Google Drive.
To keep it quick and low-maintenance, every entry (photo, video, copy&paste of a Slack discussion, etc.) was just its own file, with a filename starting with the date in "yyyy-mm-dd" format, followed by a caption. No other curation or presentation.
Even a few months after an event, there was already some significant nostalgia value (and look how far you came already), and it also was a partial chronology.
Sadly we never got big or famous, but the idea was there! Most of what was in there were early pictures of the team at important events.