Add open source tickets to the join page (#3328)

## Description

This PR adds various open source tickets to the join page.


## Checklist
- [x] I have read and understood the [WATcloud
Guidelines](https://cloud.watonomous.ca/docs/community-docs/watcloud/guidelines)
- [x] I have performed a self-review of my code

pages/get-involved/join.mdx

@@ -87,6 +87,14 @@ Special considerations:
 
 We don't know the answers to these questions, and we'd love to hear your thoughts!
 
+### Open Source Tickets
+
+Some of our open-source projects have open tickets that anyone can work on.
+Here's a collection of tickets that we think are suitable for new contributors:
+
+- [ ] [Support displaying job dependencies via flows](https://github.com/WATonomous/github-actions-tracing/issues/12) ([GitHub Actions Tracing](https://github.com/WATonomous/github-actions-tracing))
+- [ ] [Support Dark Mode](https://github.com/WATonomous/watcloud-emails/issues/17) ([WATcloud Emails](https://github.com/WATonomous/watcloud-emails/))
+
 ### File Auto-Expiration Tool
 
 {/* Internal reference: https://github.com/WATonomous/infra-config/issues/1143 */}