Add @squillace as a code owner (#1469)

Follow up to #1445.  The owners and Maintainers file should be in sync: cncf/foundation#1388 (comment)

cc: @squillace

Signed-off-by: James Sturtevant <jsturtevant@gmail.com>

Author: jsturtevant

.github/CODEOWNERS

@@ -1,2 +1,3 @@
 # Global Code Owners
-* @danbugs @devigned @dblnz @jsturtevant @jprendes @syntactically @ludfjig @simongdavies @andreiltd
+* @danbugs @devigned @dblnz @jsturtevant @jprendes @syntactically @ludfjig @simongdavies @andreiltd @squillace
+