[Misc] Update contributors

Author: Mordil

CONTRIBUTORS.txt

@@ -13,7 +13,9 @@ needs to be listed here.
 ### Contributors
 
 - Cory Benfield <lukasa@apple.com>
+- Fabian Fett <fabianfett@apple.com>
 - George Barnett <gbarnett@apple.com>
+- Michael Stegeman <michael@stegeman.me>
 - Nathan Harris <nathan@mordil.info>
 - Ondrej Rafaj <ondrej.rafaj@gmail.com>
 - Tanner Nelson <me@tanner.xyz>