Hi @martinwguy
This PR adds in the vendored sources for linenoise taken from here:
https://github.com/antirez/linenoise
I've added some documentation about this as well.
I've added a small amount of build system logic in order to simplify packaging for distro maintainers who prefer to use their system installed linenoise library.
What do you think?
If all looks good I can merge to main or simplify as you prefer.