docs: Add new "howto write a lister tutorial" with unified lister api
Closed
requested to merge generated-differential-D5069-source into generated-differential-D5069-target
This adds a new tutorial which details how to currently write the new listers (both incremental or stateless). This proposes a python template file to start a new lister.
At last, this renames the previous tutorial into tutorial-2017.
Related to swh-scheduler#3073 (closed)
Migrated from D5069 (view on Phabricator)