Idyllwild resident author Joy Sikorski, writing with co-author Michael Silversher, changes the fare for this fourth season of Eduardo Santiago’s Idyllwild Authors Series when she and Silversher present their biblical historical novel, “Tamar of the Terebinths” (Whispering Voices Publications, 2013). It is the first time the series has featured an historical biblical novel. Sikorski calls…