Proper Volta support

[chrisbbreuer]

It seems like it could be a great setup once this is merged volta-cli/rfcs#46

[chrisbbreuer]

At that point, let's also improve our actions where possible. https://github.com/volta-cli/action

[chrisbbreuer]

There is a good chance that we may just develop our own package manager if I can't find a better solution than what we have right now. Certainly, no priority, but I will revisit this in a few weeks and then see where we go 😊

[chrisbbreuer]

Currently, our implementation will be a custom shell script that checks for whether node & pnpm is installed. In case it is not, node is then managed via fnm and pnpm is activated via corepack.

I don't think we would need Volta anymore unless our script turns out unstable for the masses—which it shouldn't because corepack and fnm are pretty well-tested (even though corepack being experimental still)

[chrisbbreuer]

We went with a custom script and pnpm/fnm as the node manager