[nabeleon94]

Description

Fixes #3707.

The configuration guide tells users to run pyrit list initializers, but the package only installs pyrit_backend, pyrit_scan and pyrit_shell (see [project.scripts] in pyproject.toml), so the command fails with exit code 127.

While checking the other documented CLI invocations as the issue suggests, I found a few places that still point users at the flag-style --list-* commands. Those are now a deprecated back-compat shim (_LEGACY_COMMAND_FLAGS in pyrit/cli/pyrit_scan.py, slated for removal in 1.3.0) and print a deprecation note when used:

• doc/getting_started/pyrit_conf.md: pyrit list initializers becomes pyrit_scan list-initializers (or list-initializers inside pyrit_shell).
• doc/scanner/1_pyrit_scan.py / .ipynb: the prose around the initializers cell and the techniques note now say list-initializers / list-scenarios instead of --list-initializers / --list-scenarios (the code cell already used pyrit_scan list-initializers). Both paired files have the same edit; no outputs changed.
• pyrit/cli/_cli_args.py: the --techniques and --target help text said "Use --list-converters/--list-targets"; it now says "Use the list-converters/list-targets command", which reads correctly for both pyrit_scan and pyrit_shell.

No other pyrit <verb> invocations turned up in doc/ or README.md.

Tests and Documentation

• pyrit list initializers in the project venv: exit 127 (no such executable). pyrit_scan list-initializers --help parses fine; pyrit_scan --list-initializers prints the deprecation note.
• pyrit_scan run --help shows the updated --target / --techniques help text.
• tests/unit/cli: 668 passed, 1 skipped.
• ruff check and ruff format --check clean on the touched Python files; the .ipynb still loads as valid JSON.