maintainers: add cjshearer

maintainers/maintainer-list.nix

···
     githubId = 136485;
     name = "Chad Jablonski";
   };
+  cjshearer = {
+    email = "[e-mail]";
+    github = "cjshearer";
+    githubId = 7173077;
+    name = "Cody Shearer";
+  };
   ck3d = {
     email = "[e-mail]";
     github = "ck3d";