Update free-programming-interactive-tutorials-en.md (#4649)

* Update free-programming-interactive-tutorials-en.md

Added many tutorials by w3schools

* Update free-programming-interactive-tutorials-en.md

Corrected alphabetic order.

* Update free-programming-interactive-tutorials-en.md

Changed as @SethiPandi requested.

* Update free-programming-interactive-tutorials-en.md

Co-authored-by: Seth <seth@elypia.org>

* Update free-programming-interactive-tutorials-en.md

Co-authored-by: Seth <seth@elypia.org>

free-programming-interactive-tutorials-en.md

@@ -59,12 +59,14 @@
 
 ### C Sharp
 
+* [C# Tutorial](https://www.w3schools.com/cs) - W3Schools
 * [Codeasy](https://codeasy.net/course/csharp_elementary)
 * [Learn C#](http://www.learncs.org)
 
 
 ### C++
 
+* [C++ Tutorial](https://www.w3schools.com/cpp) - W3Schools
 * [CppKoans](https://github.com/torbjoernk/CppKoans)
 
 
@@ -138,6 +140,7 @@
 
 * [CodingBat code practice](http://codingbat.com/java)
 * [Java at Codecademy](https://www.codecademy.com/courses/learn-java)
+* [Java Tutorial](https://www.w3schools.com/java) - W3Schools 
 * [Learn Java](http://www.learnjavaonline.org)
 * [Learneroo Java tutorial](https://www.learneroo.com/modules/11)
 
@@ -151,6 +154,7 @@
 * [JavaScript Algorithms and Data Structures Certification](https://www.freecodecamp.org/learn/javascript-algorithms-and-data-structures/basic-javascript)
 * [Javascript interactive tutorial on CodeCademy](https://www.codecademy.com/learn/javascript)
 * [JavaScript interactive tutorial on CoderMania](http://www.codermania.com/javascript/lesson/1a/hello-world)
+* [JavaScript Tutorial](https://www.w3schools.com/js) - W3Schools
 * [Javascripting](https://github.com/sethvincent/javascripting)
 * [Learn JavaScript](http://www.learn-js.org)
 * [Learn knockout.js](http://learn.knockoutjs.com)
@@ -212,6 +216,7 @@
 ### Node
 
 * [Node School](http://nodeschool.io)
+* [Node.js Tutorial](https://www.w3schools.com/nodejs) - W3Schools
 
 
 ### NoSQL
@@ -234,6 +239,7 @@
 
 * [CodeCademy PHP](https://www.codecademy.com/learn/php)
 * [Learn PHP](http://www.learn-php.org)
+* [PHP tutorial](https://www.w3schools.com/php) - W3Schools
 
 
 ### Python
@@ -244,6 +250,7 @@
 * [Learn Python Step by Step](http://www.techbeamers.com/python-tutorial-step-by-step)
 * [Python for Everybody - Interactive](https://runestone.academy/runestone/books/published/py4e-int/index.html) - Barbara Ericson
 * [Python Koans](https://github.com/gregmalcolm/python_koans)
+* [Python Tutorial](https://www.w3schools.com/python) - W3Schools
 
 
 ### Ruby