Added links to readthedocs.org and apiary.io in README
Added links to readthedocs.org and apiary.io in README

Change-Id: Id4afc169dae8ac32f431ad9ecd8f119d05dfe25e

SanMi86/doc-kurento,Kurento/doc-kurento,Kurento/doc-kurento,Kurento/doc-kurento,SanMi86/doc-kurento,SanMi86/doc-kurento,SanMi86/doc-kurento