Add config so users can upload images in the description field

[virgile-dev]

Is your feature request related to a problem? Please describe. To add an image to a feature you need to host it elsewhere. Many options are out there (github, wordpress, Imgr etc.). The issue is not all users are saavy enough to find the right link that will allow image the image to render (with nextcloud the link is kinda hard to find) and using the Image : {{http://image.url.com}} syntax can be a bit tricky.

Describe the solution you'd like I'd like uMap to have a configuration variable so that an admin can setup a storage for the user's images (ex: S3) I'd like uMap to have an interface that allows users to understand how to add an image in their description (ex : Drag and Drop in the text field (like Github) or even and a button with a photo Icon (which would lead us to actually having a rich text editor like Quill.js) Describe alternatives you've considered See above how users find solution.

Additional context This would not have to be setup on every instance and be at the admin discretion.