Update GSoC 2026 page with new details

Added submission instructions. Updated mentor information and added task link for MQTT support implementation.

Author: wslany

pages/development/google-summer-of-code/2026.md

@@ -16,6 +16,8 @@ We are thrilled to share our carefully curated project ideas for this year's Goo
 
 These ideas are just some topics we came up with, where currently nobody is working on. However, Catrobat is a project with a wide range of possibilities and we're aware of our blindspots: So let's live the spirit of Open Source and come up with improvements (e.g., new features, extensions, ...) that are related to the project and in which you're interested in. We do have many senior contributors who would be happy to mentor such a project. Don't be shy and check out the last point on the list: Your idea!
 
+For your submission, please follow <a href="https://docs.google.com/document/d/1vOGY2C80raXLV6RVRHXoqiAhcnBJFeZdU8wqMm-Rgo0/edit?usp=sharing">our instructions</a> and submit a corresponding document via the <a href="https://summerofcode.withgoogle.com/">GSoC application site</a>.
+
 ## AI tools policy
 {: .no_toc }
 
@@ -46,9 +48,10 @@ You may use AI tools as much as you like (brainstorming, code generation, refact
 
 {: .highlight  }
 > **Required Skills**: Kotlin, Android-Development, Agile Development, Test Driven Development, Clean Code<br>
-> **Possible Mentors**: Wolfgang Slany, XXXXX <br>
+> **Possible Mentors**: Wolfgang Slany, Paul Spiesberger <br>
 > **Expected Outcome**: Two new bricks for sending and receiving MQTT messages<br>
-> **Difficulty level**: Advanced 
+> **Difficulty level**: Advanced
+> **Task link**: [View task](https://docs.google.com/document/d/1jw87hf8iq5DStlKOhT9yvQP7trsnzgZ6jYcH99BxBMs/edit?usp=sharing)
 
 Implement MQTT support for the Catrobat language in Catroid (Pocket Code and its flavors) so Catrobat programs can publish/receive network messages for multiplayer games, IoT, and Home Assistant setups. Add two new Catrobat bricks (activated via app settings):
 - Broadcast … via MQTT on channel …