Add arrows below x-axis

[thuyvlu]

trafficstars

Hi,

I wonder if it is possible to add arrows pointing to left and right with corresponding captions below the x-axis like in the following image.

Thanks!

[Source: Stackoverflow]

[gforge]

Thank you for this suggestion, shouldn't be that hard to add but unfortunately I lack the required time at the moment. I would love to merge a PR for this though