If you go into your account menu by clicking your name on the right side of the site header, and from there go to "Account details", you can edit the about section there as well as all other forms of profile customization
I looked into this a bit and it seems like Instagram is restricting embeds a lot more these days than they used to, so it might actually be a bit tricky. Basically it only really works reliably if you're logged in with an Instagram account, which restricts the functionality a bit. That being said, I'm looking into a third party solution for this which will provide at least partial functionality, so stay tuned!twitter and youtube posts are working great. i tried to make a post from my instagram account, and the media icon says error, instagram is not listed in the media menu. i was wondering if you were adding that, in the future?