I run emacs at work on a system that does not access the internet, so I cannot utilize the package interface that pulls directly from [melpa](https://melpa.org) (and [elpa](https://elpa.gnu.org) etc). Years ago, someone copied a version of melpa into a local directory on the air-gapped server. In my init.el, I setq package-archive to something like `(("local-melpa" . "/path/to/the/melpa/dir"))` so that it points to this local directory. I'm wondering if there is a tool to facilitate this sort of mirroring? I would like to update my packages on this air-gapped network. I am able to copy files onto the system from a less restricted workstation with internet access. Is it just a matter of unzipping the melpa repo and pointing `package-archive` to the fresh melpa directory?