I'm not eligible yet to create one, but will be soon, and I'm very interested in contributing to the community in addition of answering questions.
A pretty roughly formatted list lives here: https://stackoverflow.com/tags/tag-wikis
It's a bit complicated, because in some circumstances it's possible to have orphaned tag wikis that don't correspond to any valid tag. See https://meta.stackexchange.com/a/114184. The list of these is apparently only available to moderators.