added mschneider to maintainers

Changed files
+4
maintainers
+4
maintainers/maintainer-list.nix
···
email = "matthew@wellquite.org";
name = "Matthew Sackman";
};
+
mschneider = {
+
email = "markus.schneider.sic+nix@gmail.com";
+
name = "Markus Schneider";
+
};
mschristiansen = {
email = "mikkel@rheosystems.com";
github = "mschristiansen";