update start-course link in README to reflect correct template name

Author: BethanyJep

README.md

@@ -36,7 +36,7 @@
  [GitHub Actions](https://docs.github.com/actions) will AUTOMATICALLY UPDATE YOUR README WITH THE NEXT STEP
 
 
-   [![start-course](https://user-images.githubusercontent.com/1221423/235727646-4a590299-ffe5-480d-8cd5-8194ea184546.svg)](https://github.com/new?template_name=JS-Journey-to-AI-Foundry&template_owner=Azure-Samples)
+   [![start-course](https://user-images.githubusercontent.com/1221423/235727646-4a590299-ffe5-480d-8cd5-8194ea184546.svg)](https://github.com/new?template_name=JS-AI-Build-a-thon&template_owner=Azure-Samples)
 <footer>
 
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