added common array methods and examples for reference

[MohamedAkeelK]

created array methods reference file created markdown file for array methods

current methods added

Array.prototype.push()
Array.prototype.pop()
Array.prototype.push()
Array.prototype.shift()
Array.prototype.unshift()
Array.prototype.splice()
Array.prototype.slice()
Array.prototype.concat()
Array.prototype.join()
Array.prototype.indexOf()

Array.prototype.forEach()
Array.prototype.map()
Array.prototype.filter()
Array.prototype.reduce()

[Brandon-Alvarez-03]

@MohamedAkeelK This is AWESOME!

A couple of quick notes before merging this pull request

1. Correct the very last console.log in the arrRef.js file. it says expected output is 10 but I believe it should be 6
2. Please be more descriptive in your pull request comment
3. The addition of the supporting markdown is excellent, however, you can just name it array-methods-reference.md instead of readme to avoid any confusion (thank you for being patient while we sort out templating and file structure/naming conventions)
4. Please add concise comments in the mark down file above each array method

Essentially the goal is to have every piece of code commented and explained thoroughly so there is no room for confusion!

As soon as those changes are made your pull will be accepted. Nice work and thank you!

[MohamedAkeelK]

Love the structure 💪 Just updated, let me know if this works.

[Brandon-Alvarez-03]

@MohamedAkeelK Beautiful! This looks great. Everything works and it's easy to follow the supporting comments. Accepting your pull!