Try to make extra commands more obvious based on a suggestion from Sjors:
https://github.com/bitcoin/bitcoin/pull/31679#issuecomment-2922787970i
When `bitcoin` is invoked with no arguments, still show short help output, but
now explicitly state that more commands are available and `bitcoin help` will
list them.
Also:
- Get rid of -a/--all option. Just show all commands when `bitcoin help` or
`bitcoin --help` is used. It maybe a helpful to add an option like this if
more commands are added in the future, but right now there are not very many.
- Just show name of executable, not full path of executable in help output. This
can be a little easier to read if the path is long.
Intended to make bitcoin command line features more discoverable and allow
installing new multiprocess binaries in libexec/ instead of bin/ so they don't
cause confusion.
Idea and implementation of this were discussed in
https://github.com/bitcoin/bitcoin/issues/30983
Co-authored-by: Sjors Provoost <sjors@sprovoost.nl>
