We want to roll out the article placeholder to the first wikis. In order to give them an easy way to try out the feature we should start with making it a beta feature.
https://www.mediawiki.org/wiki/Beta_Features/Package has documentation about how to do this:
[ ] Brief, clear name
[ ] Simple, instructive description
[ ] Consistent, figurative illustration
[ ] Link to brief, helpful, translatable page on MW.org
[ ] Link to the talk page of the above, configured as a Flow board
[ ] Browser and platform compatibility is configured
[ ] Other beta feature dependency is configured
[ ] Get prelim design review
[ ] Get prelim security review
[ ] Get prelim performance review
[x] Make sure there is someone on point for feedback
[ ] Make a Phabricator project for the extension
[ ] Enable the Final Version of the code on Beta Cluster at least a week before you want to go for production.
[ ] Make gerrit change (do not merge) to the BF whitelist in mediawiki config
[ ] Deploy!