Database Design course added (#10102)

* added udemy course for database

* slash removed

* alphabetical order

* space removed

courses/free-courses-en.md

@@ -499,6 +499,7 @@
 
 * [15-721 Advanced Database Systems (Spring 2023)](https://www.youtube.com/playlist?list=PLSE8ODhjZXjYzlLMbX3cR0sxWnRM7CLFn) - CMU Database Group
 * [CMU Intro to Database Systems](https://youtube.com/playlist?list=PLSE8ODhjZXjaKScG3l0nuOiDTTqpfnWFf) - CMU Database Group
+* [Database Design and Management](https://www.udemy.com/course/database-design-and-management) - Visual Paradigm (Udemy)
 * [Database Systems](http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-830-database-systems-fall-2010/) (MIT's opencourseware)
 * [Database Systems - Cornell University Course (SQL, NoSQL, Large-Scale Data Analysis)](https://www.youtube.com/watch?v=4cWkVbC2bNE) - Professor Immanuel Trummer, freeCodeCamp.org
 * [DBMS Placement Series](https://youtube.com/playlist?list=PLDzeHZWIZsTpukecmA2p5rhHM14bl2dHU) - CodeHelp by Babbar