MAINTAINERS.md: Update to reflect reality
MAINTAINERS.md: Update to reflect reality

I realized that I should probably edit MAINTAINERS.md to move myself to
emeritus status, since I will no longer be spending >20% of my time on
Telepresence.

And when I went to do so, I realized that the list is entirely out of
date; no one listed is still spending their day-to-day working on
Telepresence (though still making the occasional contribution).

Meanwhile; Thomas, Donny, and Jose have effectively been maintainers for
many months (13, 9, and 4 respectively).  So I'm using my final action as
maintainer to put-forward granting them maintainer status (that really
they effectively already have, but you know, gotta follow GOVERNANCE.md).

I did not include Nick in the list of added maintainers, as he has only
been contributing for about a month, and GOVERNANCE.md specifies 2-3
months before being added to the list of maintainers.  I have no doubt
that in 1-2 more months the other maintainers will agree to add him to the
list:

    * Nick Powell, [njayp](https://github.com/njayp), <nickpowell@datawire.io>

I am including all removed maintainers as reviewers on this PR: in order
to (1) ask that they agree to grant maintainer status to Thomas, Donny,
and Jose ("confer and decide" in the terms of GOVERNANCE.md); and (2) ask
that they volunteer to be moved to emeritus status as they aren't
"performing their maintainer duties" (per GOVERANCE.md) (I'd vastly prefer
to not have to call a vote of maintainers to move anyone who doesn't
volunteer, I'm not trying to force anyone out here, just acknowledge the
reality of the situation).

Signed-off-by: Luke Shumaker <1abe3165bcc8c29e8b31e5c88636540fb9350004@datawire.io>

datawire/telepresence,datawire/telepresence,datawire/telepresence