docs: more updates to the contribution guide

Author: JamesIves

CONTRIBUTING.md

@@ -17,6 +17,6 @@ The core requirements for this project are:
 2. Once discussed and agreed upon, clone the project and base your changes on the `beta` branch.
 3. Make your changes.
 4. Validate your changes; at the very least, please build the image and start a server. [You can learn how to build the images using the guide located here](container/README.md).
-5. Submit a pull request to the `beta` branch.
+5. Submit a pull request to the `beta` branch. Be sure to add the appropriate reproduction steps and tests if applicable.
 6. Once reviewed, your changes will be made available on DockerHub via the `-beta` tag, for example `jives/hlds:cstrike-beta`.
 7. After some more tests, changes will be merged into the `main` branch where the production images will be published. This step will be performed by a project maintainer.