Have an experiment group (`sectionlevelimages`), add tooling to make it easy for testers to opt-in to it, etc
# Should be able to ....
#### Completion checklist
 The patches have been code reviewed and merged
 The task passes its acceptance criteria
 There are existing and passing unit/integration tests
 Tests for every involved patch should pass
 Coverage for every involved project should have improved or stayed the same
**Design & QA**
 If the task is UX/Design related: it must be reviewed and approved by the UX/Design team
 Must be reviewed and approved by Quality Assurance.
 Related and updated documentation done where necessary
- Internal technical changes: internal repository documentation must be updated (README.md, JSDoc, PHPDoc)
- Infrastructure technical changes: technical changes that reflect on environment, infrastructure, endpoints or any other area of interest for technical contributors should be reflected on [[ https://www.mediawiki.org/wiki/Extension:GrowthExperiments | Extension:GrowthExperiments ]] or [[ https://www.mediawiki.org/wiki/Extension:GrowthExperiments/Technical_documentation | Extension:GrowthExperiments/Technical documentation ]] pages.