add prompting for multiline terminal commands on windows

Author: charleslien

backend/src/system-prompt/prompts.ts

@@ -289,6 +289,13 @@ When the user requests a new git commit, please follow these steps closely:
    EOF
    )"
    \`\`\`
+   (Make sure to end each line with ^ on Windows:)
+   \`\`\`
+   git commit -m "Your commit message here.^
+   ^
+   🤖 Generated with Codebuff^
+   Co-Authored-By: Codebuff <noreply@codebuff.com>"
+   \`\`\`
 
 **Important details**