feat: try bun then node

[nobkd]

This is just a concept idea, and was only tested on my Linux machine for now

[tipiirai]

Looks great! Would simplify the installation docs a lot

[nobkd]

This behavior (of first using bun, if bun not found, using node) would still have to be mentioned in the docs.

note: I'll now test if this works on my windows vm, (using bun link from nuekit dir) to see, if this shebang is even used on windows, or if this depends on the package manager with which the package was installed.

Update:
Doesn't work on windows, because it fails to find the /bin/sh executable... Not sure, if this is possible, then.

[nobkd]

I don't see a way forward now (with Windows), but might revisit this in the future, if I find a clue, on how to proceed.

Closing for now (sadly)