We want to add some new fields to the ReadingDepth schema to support several things:
* page_id for identifying red links (original report: T208478)
* revision_id linking revisions cheaply in the database (original report: T208275)
= Precursor
[x] https://meta.wikimedia.org/wiki/Schema:ReadingDepth has been updated to include the new fields and the new revision field is mentioned in the acceptance criteria. Edit should be done by @Tbayer and @Groceryheist
= Acceptance criteria
[] `pageID` field is being sent for all pages where page_id is available (this excludes Special: pages, i.e. namespace -1)
[] `revisionID` field is being sent for all pages where rev_id is available (this excludes Special: pages, i.e. namespace -1)
[] The schema should be bumped to 18559669 in WikimediaEvents
[] The two new fields should be added where available from mw.config
= Developer notes
All information needed is available:
```
mw.config.get('wgArticleId')
mw.config.get('wgRevisionId')