Please provide documentation on how to add update rule for a just-install entry

[luzpaz]

This page was linked from the section: https://github.com/just-install/registry#submitting-new-entries (from the note at the bottom of this section).

But there is no visible documentation on how to do this.

[pgaskin]

Currently there isn't any documentation, but there are plenty of examples in jiup/rules/rules.go. Just copy one which is similar to what you want and base it on that (and remember to keep them in alphabetical order).