[SUGGESTION] Why not add a "Boards->Add .ZIP core" menu option à la already existing "Include library->Add .ZIP library"?

I mean...it would be cool if user could download a .zip/.tar.gz/... file containing all necessary files defining a new 3rd-party core and he could "manually" add it to the IDE with this proposed menu options. Why? Because there are some situations where Internet access is not suitable (laboratory schools, for instance) but a LAN shared folder with these .zip/.tar.gz...core files could do the trick.

If this suggestion doesn't like you, at least I think there should be step-by-step instructions (like these https://www.arduino.cc/en/Guide/Libraries#toc5) to guide where to put the extracted content from a .zip/.tar.gz/... core file already download.

Thanks

Start by reviewing the existing “Include library > Add .ZIP library” flow and the linked Libraries guide. The requested outcome is either an offline menu option that adds a packaged third-party core, or step-by-step documentation for manually extracting and installing one; the issue does not name implementation files or tests.

Written by the indexing model from the issue text.