earlyYou can list something and you can start from a template. Installing a plugin is not built yet, and the plugin format does not exist.

Templates and plugins for voidbase

Written by the people who use it, listed here, hosted in their own repositories. Submitting one is a GitHub issue, and the registry behind this page is a file in a public repository you can read and argue with.

What works today, and what does not

You can list a template
Open an issue, an automated audit reads the repository and reports what it found, and a maintainer decides. Accepted templates appear here with that report attached.
You can start from a listed template
Through GitHub's own Use this template button, which clones it into your account. That is the whole mechanism, and it is somebody else's.
You cannot install a plugin
pb_plugins does not exist. There is no format, no loader, and nothing to install into. Plugin submissions are open regardless, because what people want to build should shape the format rather than the other way round. None registered yet.
There is no account, and nothing to pay
No sign-in, no downloads counted, no ranking. When creators can charge for what they publish it will be written down on the pricing page before it is built.