There's a merged pull request on the void-packages repository

Improved wrksrc variable documentation
https://github.com/void-linux/void-packages/pull/18977

Description:
As a new contributor the behavior of the `wrksrc` variable in package template files confused me and led to some confusing "cannot access wrksrc" errors when a package's `distfiles` are not named what `xbps-src` expects them to be by default.

This PR adds what I learned about `wrksrc` and how it ties to `distfiles` to the documentation.