If the playground, a community-edited resource, isn't updated enough, why would another wiki? The playground is a wiki
google:
wi·ki
/?wik?/
Noun
A Web site developed collaboratively by a community of users, allowing any user to add and edit content.
.. which the playground is.
By the way, Wikipedia is a website/specific project; you can't have "a" wikipedia. A wiki is the word you are looking for (it's like the difference between a planet and Mars)