Using positional args in shell is great!

However:

• It is harder to demo because people don't know what the positional args are for
• For the same reason, Dagger executions in scripts (like in a CI yaml) will prefer to use dagger call
• This makes it less clear when we show "see the same thing we ran locally runs in CI" if that then has to be translated from shell to call

I'm proposing the option to use flags for required args in shell to avoid the split between call vs shell. This will make it reasonable to use shell -c in scripted environments like CI.

Example:
Dagger Call: - dagger call build --aaa 111 --bbb 222 --ccc 333 test out
Current option for shell: - dagger shell -c "build 111 222 333 | test | out"
Proposed option: - dagger shell -c "build --aaa 111 --bbb 222 --ccc 333 | test | out"