Documentation: "kernel_params" option

[vielmetti]

Is your feature request related to a problem? Please describe.

In netbootxyz/netboot.xyz@be90bb7 there is an additional option "kernel_params" that was added, but I don't see any documentation for it.

We have a need in some circumstances to override the console location and configuration on some systems, it looks plausible that the "kernel_params" option might provide that capability but I'm unclear as to how it's intended to be used.

Describe the solution you'd like

Brief documentation on how to use the "kernel_params" option to override kernel defaults, and some worked out use cases where that makes sense.

Describe alternatives you've considered

The other thing that had come up in discussion was a request specifically to parameterize the TTY console options, but if there's a more general way to do it that already works we can follow that path.

Additional context