MAINTAINERS: Add myself

I'd like to apply for this position, let me know if you need a CV :)

Signed-off-by: Jussi Kukkonen <jkukkonen@vmware.com>

Author: Jussi Kukkonen

docs/MAINTAINERS.txt

@@ -40,3 +40,7 @@ Maintainers:
     GitHub username: @joshuagl
     PGP fingerprint: 08F3 409F CF71 D87E 30FB D3C2 1671 F65C B748 32A4
     Keybase username: joshuagl
+
+  Jussi Kukkonen
+    Email: jkukkonen@vmware.com
+    Github username: @jku