Update hooks/post-checkout.ps1.sample

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: amondnet

hooks/post-checkout.ps1.sample

@@ -1,5 +1,5 @@
 #!/usr/bin/env pwsh
-# Post-specify hook: Runs after feature branch and directory creation
+# Post-checkout hook: Runs after feature branch and directory creation
 # Arguments: $args[0] = feature description
 # Environment: $env:BRANCH_NAME, $env:SPEC_FILE, $env:FEATURE_NUM available