Add ability to add alt text to profile picture

[alimony]

Is your feature request related to a problem? Please describe.

Posted images support alt text, it would be nice if one could be added to your own profile picture too.

Describe the solution you'd like

It could use the same or similar UI as post pictures.

Describe alternatives you've considered

Some people add a profile picture alt text in their description.

[hkolbeck]

It should be possible to set for the profile header as well. I realize that it's probably not appropriate to read a pfp description on the timeline, but it's so important to understanding someone's profile.

This has been discussing for quite some time, it would be great to hear an update.

[hkolbeck]

This came up again today, so I'm hoping to put this back on people's radar.

[mletterle]

Adding a 👍🏻 because this feels like it could be an easy win with an outsized benefit.

[erikao]

adding another +1. would be amazing if this was extended to alt text for the banner image as well. both an accessibility benefit and an easier way to add image credits.