Support short channel matching

[IanButterworth]

On julia you can do --start=no to control --startup-file=no because there's no other arg that matches --start

It would be nice if juliaup did the same for channel names

So julia +n for nightly. julia +r for release. etc.

[LilithHafner]

Sure, as long as it's only the words that are matched, not the version numbers (see #838 (comment))

[davidanthoff]

First of all, sorry that I didn't chime in on this for so long, especially to the two PR authors.

I thought about it, and I have to admit, I'm not a fan of any auto-matching solution. I think what would we could consider instead is support for channel aliases, and I think they could cover this case here, plus be more powerful overal.

The idea would be that one could do something like juliaup alias create r release to create an alias named r for the channel release. And then we would also need correspondingly juliaup alias remove and probably juliaup alias status or something like that.

Or maybe we could extend the existing link command to cover this, for example juliaup link r +release. Maybe that would actually be the nicest solution.

[StefanKarpinski]

I also think that aliases would be the best approach here.