Feature Request - Add Setter For Indentation

[StrohmyerTR]

e.g.
renderjson.set_indentation(2); // adjust space-count
or
renderjson.set_indentation(' '); // allow tabs or spaces
or
renderjson.set_indentation('space', 2); // self-explanatory
or...
infinite number of ways to implement this, please consider it.