fix: add helm

[afterthought]

functional, but could use improvements.

Off the top of my head:

I run dependency update inside a genrule. This requires env vars as passthrough to login to helm because otherwise, the genrule cannot see the context from a previous login.

Documentation for ENV vars.

[afterthought]

I'm not in a rush to merge this. I am slowly making some improvements. I did manage to find a nice clean way to remove the login code (using system library to point to ~/.config/helm.....). I'll post an update once I hit a decent stopping point.