I’m all for covering Christianity in school textbooks. In fact there should be sections dedicated to:

The corruption of the early Church.
The Crusades.
The idea of indulgences that led to the protestant reformation.
The inquisition.
The use of christianity to kill or convert native populations.
The use of christianity in the witch hunts both in Europe (outside the inquisition)
and the Americas.
The use of christianity to justify slavery.

It could go on and on. Really it could. They want to pillory islam and make christianity out to be morally superior, let’s get real with them. One of the best books I ever read was the medieval underworld. Very interesting read about the early church and the “dark ages” before the enlightenment.