style: add endLine parameter to GHA warning output format

Update the review-pr skill document to include the endLine parameter in the GitHub Actions workflow warning output format.

Author: rickeylev

tools/private/reviewbot/skills/review-pr/SKILL.md

@@ -13,14 +13,15 @@ that an automated formatter can handle. Be constructive and concise.
 
 For every issue or improvement you identify, you MUST output the finding in the
 GitHub Actions workflow command warning format. Specify the exact file path
-and line number that the comment applies to.
+and line numbers that the comment applies to.
 
 Format each finding exactly as a single line to stdout matching this template:
-`::warning file={file_path},line={line_number},title={category}::{comment_body}`
+`::warning file={file_path},line={line_number},endLine={end_line},title={category}::{comment_body}`
 
 Where:
 *   `file_path` is the relative file path from the repository root.
 *   `line_number` is the starting line number in the file where the comment applies.
+*   `end_line` is the ending line number in the file where the comment applies (equal to line_number if the issue is on a single line).
 *   `category` is a short tag for the type of issue (e.g., "Error Handling", "Correctness", "Performance").
 *   `comment_body` is your constructive and concise feedback.