Put all your online profile links in a tweet and pin that tweet? Or in your Instagram profile? Or in Medium (in your about section)... What you are asking for

Put all your online profile links in a tweet and pin that tweet? Or in your Instagram profile? Or in Medium (in your about section)... What you are asking for is something like allyourprofiles.com/gajus where you can put all your online profile links... but why do you need the indirection? Just use one of your already existing social media profiles and use it as your "entry point": from there provide a link to all your other profiles. Easy.