docs: reorganize files into logical folder structure

- Move PRE_COMMIT_HOOKS.md to development/ (development-focused)
- Move APP_NAME_CONFIGURATION.md to setup/ (configuration-focused)
- Move ENVIRONMENT_VARIABLES.md to setup/ (configuration-focused)
- Improves organization by grouping related documentation together
- Makes it easier to find relevant docs based on purpose

docs/setup/ENVIRONMENT_VARIABLES.md

@@ -533,6 +533,6 @@ Choose the approach that best fits your workflow:
 
 For more information, see:
 
-- [Kustomize README](../k8s-kustomize/README.md)
-- [Migration Guide](../KUSTOMIZE_MIGRATION.md)
-- [Deployment Scripts](../scripts/)
+- [Configuration Guide](COMPLETE_TEMPLATE_CONFIGURATION.md)
+- [App Name Configuration](APP_NAME_CONFIGURATION.md)
+- [Project Structure](../architecture/PROJECT_STRUCTURE.md)