I'm creating notes containing a URL e.g. to an image, PDF, GIF, reddit self text etc and want Joplin to download the contents at that URL and insert or attach it to the note. Is that possible? If not built-in I'd be happy to create a plugin.
I looked at this answer but the repo 404s and it doesn't seem to do quite what I want anyway.
If you create those notes you can use joplin‘s webclipper to put the content of a webpage into a new note.
But I do not know any tool or plugin, that saves the content of an url in an existing note into the same note, e.g. by inserting it as a new paragraph.
Please check https://discourse.joplinapp.org/t/web-clipper-for-android/25860. I've been using this combination myself, and I think it's quite a decent alternative to Web Clipper (albeit less functional, but as long as the website isn't something funky, it should work fine).