Add networkx's `random_regular_graph`

[frankharkins]

From what I can tell, there is no Rustworkx equivalent to the random_regular_graph feature.

If it's possible to create a random regular graph using one of rustworkx's existing methods, then it'd be good to name-drop random_regular_graph in that method's docs page.

[IvanIsCoding]

I don’t think we have generators for regular graphs, but that could be added

[singhmeet11]

Hi @IvanIsCoding and @frankharkins, I would love to take care of this.

[IvanIsCoding]

Good, I assigned the issue to you