In order to provide a better reading experience through a large set of users, we want to be able to allow users to increase and decrease the font size of articles.
- font changer is promoted to stable (turning on beta does not provide access to the feature) in the feature branch 'specialpages'
- font changer appears in "Settings" tab separate from beta
Review notes (which are likely to be outdated) in T109363
Do not deploy this until T169369: Change font size controls to use small, regular, large and extra large buckets and additional QA is complete