The GitHub wiki is not ideal for contributions because it only allows direct commits. However, we can include a workflow that takes the the pages from some directory (e.g. docs/ or wiki/) and pushes them into the GitHub wiki. Here's an example of workflow that does that: https://nimblehq.co/blog/create-github-wiki-pull-request.

That would allow opening PRs for modifying wiki pages, which would vastly improve the contributions quality and thus the wiki quality.