Add Vanilla js Concepts

[divyanshu-rawat]

Add more vanilla js concepts, for example, feel free to explore this repo.

[Barathwaja]

Hi @divyanshu-rawat , What needs to be done exactly?? Give a glimpse so that I can try helping out.

[divyanshu-rawat]

@Barathwaja feel free to add anything that explains vanilla js concepts constructors, operators etc.

[raindogg]

Hi! I submitted this PR for this issue. Let me know if this is the kind of thing you are looking for. Thanks!

[peterekepeter]

I've submitted a PR I think it's a pretty practical tutorial on how to use the array methods.