Enhance instructions with prompt guidance

Added prompt guidance for Copilot CLI usage.

Author: arilivigni

.github/instructions/copilot-cli-ref.instructions.md

@@ -2,6 +2,11 @@
 applyTo: "**/**"
 ---
 
+# Prompt guidance
+
+Stick to the prompts and context being provided don't jump ahead to doing steps
+Only add, commit, and push files when prompted by the user
+
 # New features
 
 Use .github/ISSUE_TEMPLATE/feature_request.md to request all new features for calculator.js.
@@ -83,4 +88,4 @@ To learn about what I can do:
 /theme [show|set|list] [auto|dark|light] - View or configure terminal theme
 /usage - Display session usage metrics and statistics
 /user [show|list|switch] - Manage GitHub user list
-```
+```