Adds 'migrate to zod' prompt file

Author: martinlingstuyl

.github/prompts/migrate-command-to-zod.prompt.md

@@ -0,0 +1,15 @@
+---
+mode: agent
+tools: ['codebase', 'editFiles', 'changes']
+---
+Update the command file to use ZOD. 
+- Don't change the command's functionality. 
+- Update tests accordingly. 
+- Don't remove or add new tests. 
+- For updating test files, check how spec.ts files have been modified in the reference implementations. 
+- Use the .mdx file if you need additional information about the command's options. 
+
+Use the following git commits as reference implementations for a command and its test using ZOD:
+
+- 824c1ebd2dfb0a1eabb623ed6a22da50f4edf61d
+- 3410857272d39e16fe498823a1df9f320b1021dd