I hope I got this right.

In general, this should help to capture unintentional errors

Tests fail now, not clear why yet.

Review command line argument parsing

See merge request mpsd-cs/mpsd-software-environments!7

Specify expanded toolchain help for all commands.

See merge request mpsd-cs/mpsd-software-environments!8

fix import order as the standard suggests

See merge request mpsd-cs/mpsd-software-environments!6

- reinstall needs to know toolchain(s) as well.

Only 'install' needs to know about --ALL, etc.

(probably introduced by myself when breaking long lines in last MR)

(use `isort`)

Execute tests on CI system

See merge request mpsd-cs/mpsd-software-environments!4

allow CI to fail if ruff or black is unhappy, and format source to make it pass

See merge request mpsd-cs/mpsd-software-environments!3

- no attention or change to contents
- tests not executed

triggered by discussion https://gitlab.gwdg.de/mpsd-cs/mpsd-software-environments/-/merge_requests/3#note_803951

- didn't pay attention to content
- didn't intend to change content or behaviour
- didn't execute tests

Resolve "First draft for user interface for top level install command"

Closes #2 and #1

See merge request mpsd-cs/mpsd-software-environments!1

first attempt to have tests (fake tests only)

See merge request mpsd-cs/mpsd-software-environments!2

(will do style changes in separate MR / commit)