added Digital Electronics in free-courses-en.med (#7319)

* added Digital Electronics in free-courses-en.med

* added ComputerArchitecture in free-courses-en.md and added blank line

* Update free-courses-en.md

* Update free-courses-en.md

courses/free-courses-en.md

@@ -25,6 +25,7 @@
     * [SQL](#sql)
 * [Deep Learning](#deep-learning)
 * [DevOps](#devops)
+* [Digital Electronics](#digital-electronics)
 * [Docker](#docker)
 * [Elastic](#elastic)
 * [Flutter](#flutter)
@@ -389,6 +390,11 @@
 * [Intro to DevOps](https://www.udacity.com/course/intro-to-devops--ud611) - Karl Krueger, Dwayne Lessner, Gundega Dekena (Udacity)
 
 
+### Digital Electronics
+
+* [Digital Electronics](https://www.youtube.com/playlist?list=PLBlnK6fEyqRjMH3mWf6kwqiTbT798eAOm) - Neso Academy
+
+
 ### Docker
 
 * [Docker](https://www.youtube.com/playlist?list=PLhW3qG5bs-L99pQsZ74f-LC-tOEsBp2rK) - Raghav Pal