Images overhaul
- We want images to be uploadable with the editor.
- After submitting a proposal, images attached to it should be linked to said proposal.
- Occasionally, images not linked to any model should be deleted if they were created_at more than n days ago.
- Caroussel feature display of images should be removed
- Existing images should be migrated to appear at the bottom of existing proposals.
- Images linked to a proposal should remain visible in the image section of a proposal. (?)
- Or do we want to remove the separate images section and only store images that are included in the markdown.