"As a Client Developer, I want to read pages on the API Portal with the same hostname as the API endpoints, so that [...]."
We want to host the API Portal wiki at the root of the api.wikimedia.org domain. This means that we'll need to route paths like /w/ and /wiki/ to MediaWiki, and others like /core/ and /feed/ to the appropriate API backends.
https://api.wikimedia.org/wiki/Main_Page -> MediaWiki
https://api.wikimedia.org/core/v1/wikiquote/fr/Joseph_Joubert -> API
This routing could be done somewhere in front of Envoy, so that Envoy never gets requests for /wiki/, or it could be done by Envoy.