refactor: Update README.md (#7)

* Update README.md

You are changed readonly property on `updateTitle` method

* Update README.md

Author: rjurado01

README.md

@@ -30,7 +30,7 @@ import { CourseId } from "./CourseId";
 import { CourseTitle } from "./CourseTitle";
 
 export class Course {
-  constructor(readonly courseId: CourseId, readonly courseTitle: CourseTitle) {}
+  constructor(public courseId: CourseId, public courseTitle: CourseTitle) {}
 
   updateTitle(newCourseTitle: CourseTitle): void {
     this.courseTitle = newCourseTitle;
@@ -65,7 +65,7 @@ import { CourseId } from "./CourseId";
 import { CourseTitle } from "./CourseTitle";
 
 export class Course {
-  constructor(readonly courseId: CourseId, readonly courseTitle: CourseTitle) {}
+  constructor(public courseId: CourseId, public courseTitle: CourseTitle) {}
 
   updateTitle(newCourseTitle: CourseTitle): void {
     this.courseTitle = newCourseTitle;