69a7948575
Essentially, any operator modifying Blender data should enable this `UNDO` option, else bad things (corruption, crashes...) are likely to happen. * Added a new Operator example to explain this topic. * Updated some existing Operator examples that were not correct anymore. * Added a new small section in the gotchas page linking to it. * Added also short reminder about this in the `UNDO` 'tooltip' description itself. Related to #77557.