Added specific 2024 guidance for testing the Umbraco 15 RC

Author: nul800sebastiaan

contributing/hacktoberfest/contributing.md

@@ -4,6 +4,44 @@ We [have general contribution guidelines available](../README.md) for Umbraco-CM
 
 Specificially for Hacktoberfest, we have a lot more things you can get involved in!
 
+## Hacktoberfest 2024
+
+One of our main focus areas for 2024 is to deeply test out the major new features of Umbraco v15. The [release candidate for this release is available now](https://umbraco.com/blog/umbraco-15-release-candidate/) and we encourage you to test the main new features, namely:
+
+- The new rich text editor (RTE)
+  - Migrating existing RTEs to the new RTE datatype
+  - Working with the new RTE
+  - Extending the new RTE
+- Lazy-loaded content, which is replacing the main caching mechanism
+  - Upgrading existing sites and making sure everything still works on the frontend
+  - If you have any custom routing or controllers in place, do they still work as expected
+  - Try out the new `ISeedKeyProvider`, `IDocumentServices` and `IDistributedCache`
+- Block-level variants
+  - Making sure all of your existing blocks work after an upgrade
+  - If you have a very large block-based site, it is interesting to see if the upgrade doesn't take too long
+  - Add variants to your existing or new blocks and start using them: edit, save, publish, etc
+
+Once you have done a round of thorough testing, please make sure to [report any issues on the tracker](https://github.com/umbraco/Umbraco-CMS/issues/new?assignees=&labels=type/bug&labels=affected/v14&template=01_bug_report.yml&title=v15RC1) as usual. 
+
+### Making it count for Hacktoberfest
+
+We really appreciate your help in testing this release. Please make sure to describe to us in a bit of detail what you've tried, let us know a bit about the scale of project you're testing on, etc. 
+
+If everything "just" worked (🤞) then describe that as well! Let us know exactly what you focused on that worked well.
+
+You can do this by heading to the [https://github.com/umbraco/HacktoberfestActivityLog](HacktoberfestActivityLog) repository and adding your name to the list in the "Low code/no code" section. 
+
+An example of a participation entry is:
+
+`- 2024-10-04 - Paula Philips - Umbraco 15 Release Candidate testing - Details in the PR description`
+
+In the description of the pull request to get your name added, please put your test results as described above and link to any issues you've created if things didn't work as expected.
+
+{% hint style="info" %}
+This would be a great use of [the `Draft` pull request feature on GitHub](https://github.blog/news-insights/product-news/introducing-draft-pull-requests/), so you can work on testing and keep updating the description with your test results until you're done and ready to submit your final PR. 
+{% endhint %}
+
+
 ## Packages
 
 Packages are back on the menu - and yes, they also count as a contribution to Umbraco!