Feature request: add a "default" action

[lstep]

It would be cool if climax could execute a default climax.Command if no parameter is specified on the CLI.

[tucnak]

Thanks! Sounds pretty reasonable and easy to implement, will definitely do.

[tucnak]

Back here after a while. I guess we should stick to Application.Default, which is a func(Context) int for now (with some documentation arrangements probably). At the moment what you can do is:

app := climax.New("name")
// ...
app.Default = someCommand.Run

We could introduce DefaultCmd or anything, but it would most certainly add some ambiguity.