Add support for Adjusting the width of columns in realtime

[Zaeem20]

Hey Akash,

I am using your library in my project, it is very much useful when we have to display table like widget in our app,

Consider this as a suggestion, try to implement for adjusting column width like ttk.treeview, also add a parameter named as heading as an optional parameter, coz we have to manually add that in data, which make the process little bit of complex.

Overall you project is good, Appreciate your efforts.

Regards: Zaeem Durani