Effectively, we're all set up to distribute the plugin. Just a few things left.
Update the documentation, and add a README.md file to let people know what your plugin does (this can be copied from the intro of your plugin). You'll also want to add a LICENSE file, indicating the license under which you're distributing the plugin. You can distribute the plugin under the same license as Vim (:help license), or choose your own (GitHub has a helpful https://choosealicense.org for this purpose).
Now, you'll just have to turn $HOME/.vim/pack/plugins/vim-commenter into a Git repository, and upload it somewhere.
At the time of writing this book, GitHub is the go-to bastion of freedom for storing code (however, as SourceForge ...