Use builtin map instead of home-built

[md2perpe]

As I understand it, the order of FileList elements in the slice is not of importance. Therefore, instead of a slice of the struct FileList (containing Key and Value), you could use a map[string] string.

https://gobyexample.com/maps
https://blog.golang.org/go-maps-in-action

[xuri]

Thank you so much for your suggestion. I have to update package use map[string]string instead of []FileList. In addition, I intend to use the object-oriented approach reconstruction package.