Feature summary
Add the WikimediaApiPortal skin to Patch Demo, so that it can be installed on demo wikis.
Use case(s)
It's a Wikimedia-deployed skin (albeit only on one wiki - https://api.wikimedia.org), so it seems reasonable that folks might sometimes want to test out how certain changes affect it. E.g., right now I was curious whether https://gerrit.wikimedia.org/r/c/mediawiki/core/+/1203501 made a difference to how/whether notification icons were displayed for temporary accounts using that skin.
Benefits
Able to test patches out on another Wikimedia-deployed skin :)
Notes
My first impression would be that this shouldn't be added to the wikimedia preset (despite being Wikimedia-deployed), given that it's only actually deployed on one Wikimedia wiki.
