Added addAdmin Method to Administration Class

src/main/java/org/example/Administration.java

@@ -36,7 +36,7 @@ public class Administration {
         for(Admin admin : admins )
         {
             if(admin.getId().equals(AdminID)){
-                professors.remove(admin);
+                admins.remove(admin);
                 return true; //Course found and removed
             }
         }
@@ -44,6 +44,10 @@ public class Administration {
         return false;
     }
 
+    public void addAdmin(Admin admin)
+    {
+        admins.add(admin);
+    }