Fix free-courses-en.md structure (#4685)

- Remove repeated Sails.js entry from index;
- Change Assembly position to place in alphabetical order

free-courses-en.md

@@ -52,7 +52,6 @@
 * [QB64](#QB64)
 * [R](#r)
 * [Ruby](#ruby)
-* [Sails.js](#sailsjs)
 * [Scala](#scala)
 * [Security](#security)
 * [Software Engineering](#software-engineering)
@@ -81,12 +80,6 @@
 * [This is CS50x](https://cs50.harvard.edu/x/2020/) - David J. Malan (Harvard OpenCourseWare)
 
 
-### Assembly
-
-* [Introduction To Reverse Engineering Software](http://opensecuritytraining.info/IntroductionToReverseEngineering.html)
-* [Introductory Intel x86: Architecture, Assembly, Applications, & Alliteration](http://opensecuritytraining.info/IntroX86.html)
-
-
 ### Android
 
 * [Android Developer Fundamentals (Version 2) — Codelab](https://developer.android.com/courses/fundamentals-training/toc-v2)
@@ -114,6 +107,12 @@
 * [Angular Tutorial For Beginners](https://www.youtube.com/playlist?list=PLC3y8-rFHvwhBRAgFinJR8KHIrCdTkZcZ) - Codevolution (YouTube)
 
 
+### Assembly
+
+* [Introduction To Reverse Engineering Software](http://opensecuritytraining.info/IntroductionToReverseEngineering.html)
+* [Introductory Intel x86: Architecture, Assembly, Applications, & Alliteration](http://opensecuritytraining.info/IntroX86.html)
+
+
 ### Bash / Shell
 
 * [Bento Shell Track](https://bento.io/topic/shell) (Bento)