Adds a bash completion script for the new bitcoin command-line
tool, which unifies the main Bitcoin Core executables under a
single interface. This feature improves usability, reduces errors,
and makes the command-line tools more easily discoverable for users
working in a Linux bash environment.
The completion script dynamically lists available commands and options
by parsing `bitcoin --help` and `bitcoin help`. It also incorporates
the existing bash completions for `bitcoind`, `bitcoin-cli`, and
`bitcoin-tx`, depending on the argument provided (node, rpc, or tx).
This ensures that all relevant completions are available seamlessly
through a single interface without modifying core functionality.
No functional changes to core code are introduced; this is an optional
enhancement placed under `contrib/` for easy installation and use.
This naming scheme supports auto-detection and on-demand loading of completions.
See
ba109693ee/README.md (faq),
section "Where should I put it to be sure that interactive bash shells will find it and source it".
Previously, distro package maintainers had to rename these files manually.
Completions are dynamically generated from the respective binary help
pages.
Completions should be sourced into the shell or added to
$XDG_CONFIG/fish/completions.
