Hi -- is this possible? Which pane do you drag it into? And, if this feature actually exists, where should I have gone to look for the info (so that I don't bother the forum next time)?
On macOS you can drag onto the Dock icon. Dragging to a shortcut or the taskbar icon on Windows doesn't seem to do the same for some reason. We'll see if we can fix that.
But on any platform, if the file type is associated with Zotero (as it should be by default), you can of course just double-click on the file to have Zotero prompt you to open it. If the file type is associated with another program, you can right-click and open the file with Zotero that way.
Just dragging a file into Zotero currently adds it as an attachment rather than importing it, since Zotero supports a whole lot of file types, and it's not impossible that someone could want to store a supported type as an attachment. But it might make more sense to prompt to import supported types on drag, and if people really want to add such a file as an attachment, they can use the various toolbar/menu options.
Upgrade Storage
But on any platform, if the file type is associated with Zotero (as it should be by default), you can of course just double-click on the file to have Zotero prompt you to open it. If the file type is associated with another program, you can right-click and open the file with Zotero that way.
Just dragging a file into Zotero currently adds it as an attachment rather than importing it, since Zotero supports a whole lot of file types, and it's not impossible that someone could want to store a supported type as an attachment. But it might make more sense to prompt to import supported types on drag, and if people really want to add such a file as an attachment, they can use the various toolbar/menu options.