As a club captain, I'd like to see the ability to attach basic files to a club event (run, ride, row, etc.) This would be useful for things like parking maps, GPX files, participation waivers, organizational spreadsheets for group relays, and event flyers.
Example: I recently set up a group run with a starting point which was new to some of my club members, and I took the time to create a "park here" graphic, but was unable to attach that to the group event and had to create a subsequent post which not all participants saw. I also entered the specific address of the meet-up, but some folks’ navigation apps took them to somewhere else nearby (not a STRAVA issue). Although STRAVA allows for specific addresses to be used in the meet-up location, this doesn't always account for things like vehicle parking which may be a significant distance from the activity start.