Implemented enrollProfToCourse function in Main class

src/main/java/org/example/Main.java

@@ -1,4 +1,6 @@
 package org.example;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Scanner;
 
 public class Main {
@@ -44,6 +46,27 @@ public class Main {
                     break;
                 case 3:
                     // Enroll Prof to Course
+
+                    System.out.println("Please enter Professor ID");
+                    String profID = scanner.next();
+                    while(administration.findProfessorById(profID) == null){
+                        System.out.println("This Professor does not exist");
+                        System.out.println("Please enter a new Professor ID");
+                        profID = scanner.next();
+                    }
+                    System.out.println("Please enter Course ID");
+                    String courseID = scanner.next();
+                    while(administration.findCourseByID(courseID) == null){
+                        System.out.println("This Course does not exist");
+                        System.out.println("Please enter a new Course ID");
+                        courseID = scanner.next();
+                    }
+                    Professor prof = administration.findProfessorById(profID);
+                    Course course = administration.findCourseByID(courseID);
+                    List<Course> courseList = prof.getCoursesTaught();
+                    courseList.add(course);
+                    prof.setCoursesTaught(courseList);
+
                     break;
                 case 4:
                     // Drop Prof from Course