maintainers: add jyooru

maintainers/maintainer-list.nix

···
     githubId = 20658981;
     name = "Jarosław Wygoda";
   };
+  jyooru = {
+    email = "[e-mail]";
+    github = "jyooru";
+    githubId = 63786778;
+    name = "Joel";
+    keys = [{
+      longkeyid = "rsa4096/18550BD205E9EF64";
+      fingerprint = "9148 DC9E F4D5 3EB6 A30E  8EF0 1855 0BD2 05E9 EF64";
+    }];
+  };
   jyp = {
     email = "[e-mail]";
     github = "jyp";