Alt text for images and embeds.

Discord is a fantastic way to hold short-term communications, but a feature that would both improve accessibility and indexing/searching through old conversations would be the ability to provide alt text for image embeds. (alternative text, or otherwise known as a caption).

Please allow for users to write alt text for images when uploading (and allow for it to be a requirement in certain channels to include a caption). Captions/alt text could be shown when hovering the image, which currently does nothing.

In addition, please allow for moderators to edit and add/replace the caption on an embedded image. This could be useful for moderating the content of the text, but also as a way to add captions or 'tag' images for later searching purposes.