[book] typos / clarifications in create-instance section
Clarify that cubicweb-ctl upgrade needs to be run whenever cubicweb or a
cube is upgraded. Related to #2632425.
Document: cubicweb-doc
Title: CubicWeb documentation
Author: Logilab
Abstract: Some base documentation for CubicWeb users and developpers
Section: Apps/Programming
Format: HTML
Index: /usr/share/doc/cubicweb-documentation/index.html
Files: /usr/share/doc/cubicweb-documentation/*.html