gitignore : add .pi + personal SYSTEM.md (#22316)

* gitignore : add .pi + personal SYSTEM.md

* cont : fix requirements heading in PR template

* cont : shorten line

.github/pull_request_template.md

@@ -6,7 +6,7 @@
 
 <!-- You can provide more details and link related discussions here. Delete this section if not applicable -->
 
-# Requirements
+## Requirements
 
 <!-- IMPORTANT: Please do NOT delete this section, otherwise your PR may be rejected -->