Add Kevin Alvarez (@crazy-max) as maintainer

Kevin is a maintainer for BuildKit, Buildx, and Docker's official GitHub
actions (among others), has been our "in-house GitHub actions expert"
for a long time, and has made significant contributions to the integration
with BuildKit, and to improve our build pipeline(s).

Kevin would be a great addition to our list of maintainers and to allow him
to perform his work in these areas in a more official capacity.

I nominated Kevin as maintainer, and votes passed, so opening a PR to
make it official.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

MAINTAINERS

@@ -29,6 +29,7 @@
 			"coolljt0725",
 			"corhere",
 			"cpuguy83",
+			"crazy-max",
 			"estesp",
 			"johnstep",
 			"justincormack",
@@ -67,7 +68,6 @@
 			"alexellis",
 			"andrewhsu",
 			"bsousaa",
-			"crazy-max",
 			"fntlnz",
 			"gianarb",
 			"laurazard",