I have further optimized the shortcut. The deluxe version now extracts metadata like title, author, date as well as the article image and puts it back together in a form that looks good in Joplin. Besides the article title, the date is now also copied to the clipboard and can be manually pasted as title in the note.
The article is also now automatically retrieved in "Safari Reader" mode. This gives you a clean document, without ads or anything like that.
With some websites, the retrieval via "Safari Reader" does not work (for example with spiegel.de, an important German news website). For this, I have built in a query that checks whether the retrieval worked, if not, the content of the page is copied completely, in raw mode, so to speak, without formatting in the "Reader View".
The article picture is encoded as base64, because the Joplin app currently only accepts text and no files. So the image can be stored permanently in the note and not only linked.
This shortcut already works very well for me as a some kind of web clipper, but it can certainly be further optimized and adapted.
https://www.icloud.com/shortcuts/3ef4f7b15274407dbfcddc2e672514b7 (Preview)