Add Free Book & Course of Vue.js (#6398)

* Add Free Book and Course of Vue.js

* Remove Duplicate & Giving Lecturer Credits

* Update free-courses-en.md

courses/free-courses-en.md

@@ -594,6 +594,7 @@
 
 #### Vue.js
 
+* [Full Stack Vue.js, Express & MongoDB](https://www.youtube.com/playlist?list=PLillGF-RfqbYSx-Ab1xWVanGKtowTsnNm) - Traversy Media (Youtube)
 * [Get Started with Nuxt](https://explorers.netlify.com/learn/get-started-with-nuxt) - Debbie O'Brien (Netlify)
 * [Internationalization with vue-i18n](https://vueschool.io/courses/internationalization-with-vue-i18n)
 * [Intro to Vue 2](https://www.vuemastery.com/courses/intro-to-vue-js/vue-instance)
@@ -652,8 +653,8 @@
 * [Machine Learning Tutorial Python \| Machine Learning For Beginners](https://www.youtube.com/playlist?list=PLeo1K3hjS3uvCeTYTeyfe0-rN5r8zn9rw) - Dhaval Patel
 * [Machine Learning with Python - Youtube Playlist](https://www.youtube.com/playlist?list=PLZoTAELRMXVPBTrWtJkn3wWQxZkmTXGwe) - Krish Naik (YouTube)
 * [Machine Learning with Python by Saeed Aghabozorgi](https://cognitiveclass.ai/courses/machine-learning-with-python) (cognitiveclass.ai)
-* [Mathematics for Machine Learning - Linear Algebra](https://www.youtube.com/playlist?list=PLiiljHvN6z1_o1ztXTKWPrShrMrBLo5P3) - Imperial College London, Dr David Dye, Dr Sam Cooper 
-* [Mathematics for Machine Learning - Multivariate Calclus](https://www.youtube.com/playlist?list=PLiiljHvN6z193BBzS0Ln8NnqQmzimTW23) - Imperial College London, Dr David Dye, Dr Sam Cooper 
+* [Mathematics for Machine Learning - Linear Algebra](https://www.youtube.com/playlist?list=PLiiljHvN6z1_o1ztXTKWPrShrMrBLo5P3) - Imperial College London, Dr David Dye, Dr Sam Cooper
+* [Mathematics for Machine Learning - Multivariate Calclus](https://www.youtube.com/playlist?list=PLiiljHvN6z193BBzS0Ln8NnqQmzimTW23) - Imperial College London, Dr David Dye, Dr Sam Cooper
 * [Pattern Recognition and Machine Learning](https://www.microsoft.com/en-us/research/people/cmbishop/#!prml-book)
 * [PyTorch tutorials by PyTorch.org](https://pytorch.org/tutorials)
 * [Stanford University Machine Learning](https://www.coursera.org/learn/machine-learning)