[entity] Stop returning source information in cw_metainformation()
We should not need that. It has been introduced to handle things we should not
do and probably don't do anymore (e.g. attempting to grasp recursive import of
several sites).
Related to #15538288.
Tutorials
~~~~~~~~~
We present a few tutorials of different levels. The blog building
tutorial introduces one smoothly to the basic concepts.
Then there is a photo gallery construction tutorial which highlights
more advanced concepts such as unit tests, security settings,
migration scripts.
.. toctree::
:maxdepth: 1
base/index
advanced/index
tools/windmill.rst
textreports/index
dataimport/index