Create missing classes for Transcription, Corpus

Closes #135 (closed)

changed milestone to %ML Prod - August 2022 n°2

added P2 Quick Win labels

requested review from @babadie

assigned to @schneider-y

mentioned in merge request !198 (merged)

added 14 commits

• bd7fd549...007a33ec - 13 commits from branch master
• a19dad0b - create new classes

Compare with previous version

enabled an automatic merge when the pipeline for a19dad0b succeeds

merged