[Improvement] Store bookmarks in stack

[muhitsarwar]

Currently, the bookmark list is sorted by lexicographical name.

But it will be more handy during code review, if it is sorted by their creation time. Obviously there will be toggle variable to toggle this feature.

Can we do that?

I'm very new to vim. I'm loving it now. I'll be very happy if u give me some resource about vim plugin editing.
So i'll edit it myself and will create PR.

-Thanks in advance