Rename index file from indef.fr.txt to index.txt to dit Sphinx needs and adjusted conf file in consequence.
Moved images from fr/ to book/ so that images would be in central location for both en and fr books.
def postinit(vreg):
"""this callback is called at the end of initialization process
and can be used to load explicit modules (views or entities).
For instance :
import someviews
vreg.load_module(someviws)
"""
# from migration import migrate
# migrate(vreg)