Update CONTRIBUTING.md

Author: meili-bot

CONTRIBUTING.md

@@ -19,6 +19,8 @@ Thanks so much for participating with Meilisearch this year!
 2. PRs reviews will take place from Monday to Thursday, during usual working hours, CEST time. If you submit outside of these hours, there’s no need to panic; we will get around to your contribution.
 3. There will be no issue assignment as we don’t want people to ask to be assigned specific issues and never return, discouraging the volunteer contributors from opening a PR to fix this issue. We take the liberty to choose the PR that best fixes the issue, so we encourage you to get to it as soon as possible and do your best!
 
+You can check out the longer, more complete guideline documentation [here](https://github.com/meilisearch/.github/blob/main/Hacktoberfest_2022_contributors_guidelines.md).
+
 ## Assumptions
 
 1. **You're familiar with [GitHub](https://github.com) and the [Pull Request](https://help.github.com/en/github/collaborating-with-issues-and-pull-requests/about-pull-requests)(PR) workflow.**