Add a MAINTAINERS.txt entry for Drupal CLI with Moshe and dww as co-maintainers

MAINTAINERS.txt already has sections for each core module, and then a bunch of "systems" like "Form API" or "Routing". Most modules provide routes and have forms. While I might be the maintainer for "Update Status" module, a Form API subsystem maintainer is welcome to weigh in on an issue with a form inside Update Status.

I think there's a similar overlap here. The "CLI maintainers" understand the plumbing, the scripts for the "Application", the bootstrapping stuff, and (generally) the individual commands. We have an overview of the big picture. Specific commands are mostly going to be covered by the subsystem maintainers that added them (e.g. the recipe commands are under the recipe subsystem, as you point out). But also, the CLI maintainers are changing some of the details of those recipe commands based on the big picture. I don't think this needs to be formally explained in the MAINTAINERS.txt section. We can understand that the "CLI subsystem maintainers" are available for questions and reviews about the CLI system overall, and will be able to help specific issues correctly add new commands to various other subsystems. Generally, the "guts" of each command will be understood and maintained by the subsystem maintainer(s) for the module that's providing the command. But the CLI maintainers might have opinions on The Right Way(tm) to structure the command, how to write good tests for it, whatever.

Meanwhile, there's already this section:

Bootstrap
- ?

so if someone (e.g. @kingdutch) wanted to put themselves forward as the "bootstrap subsystem maintainer", they'd be most welcome to do so. 😅

All that said, @mradcliffe: Do you want to be listed as a CLI subsystem maintainer? You've definitely been driving this effort in a lot of ways, and clearly understand the inner workings.

Since #3453474: CLI entry point in Drupal Core is merged (🎉🙏), would be good to get this in, too.

Still happy for @mradcliffe to join. Based on Slack, they're still considering if they want to do it. We can always add them later. So for now, here's a rebase and non-draft MR with just Moshe and myself (for now).

Re #9 agreed. I assumed that was implied, but I just added it explicitly as a remaining task. Thanks!

Thanks!

We still need the dr - CLI system component added to the core project. I don’t think I have perms / auth to do that myself.

Sweet, thanks!