chore: update MAINTAINERS.md

Update list of current maintainers

Signed-off-by: James Curtis <jxcurtis@amazon.co.uk>

Author: JamesC1305

MAINTAINERS.md

@@ -5,7 +5,7 @@ Firecracker is maintained by a dedicated team within Amazon:
 - Egor Lazarchuk <yegorlz@amazon.co.uk>
 - Ilias Stamatis <ilstam@amazon.com>
 - Jack Thomson <jackabt@amazon.com>
+- James Curtis <jxcurtis@amazon.com>
 - Michael Zoumboulakis <zoumboul@amazon.com>
-- Nikita Kalyazin <kalyazin@amazon.com>
 - Riccardo Mancini <mancio@amazon.com>
 - Takahiro Itazuri <itazur@amazon.com>