I wish to add map(), filter() and reduce() methods in Array_Methods.js file

[aditya-464]

I wish to add map(), filter() and reduce() methods in Array_Methods.js file.

Please assign this issue to me under "hacktoberfest" and "hacktoberfest-accepted" labels

[aditya-464]

@arkalsekar please assign this issue #2 to me

[aditya-464]

Thank You @arkalsekar

[sakshi135]

Please assign this issue to me.