[igraph] Recommended values for Kamada-Kawai layout

[Matthew Walker]

Hi,

I do not know if this is the appropriate place to say this, but I found it useful to know some recommended values [1] for the Kamada-Kawai layout algorithm.  I noticed that the graphopt algorithm's documentation included such values and I found them very useful.  Perhaps we could add some recommended values to the documentation for igraph_layout_kamada_kawai()? 

I would be happy to contribute such a (minor) modification to the code's documentation, but I do not know if you would want this, nor the best way to offer it to you.

[1] http://svitsrv25.epfl.ch/R-doc/library/sna/html/gplot3d.layout.html

Cheers,

Matthew