fix: add backup in link-pr file

Signed-off-by: Xinwei Xiong(cubxxw) <3293172751nss@gmail.com>

.github/workflows/link-pr.yml

@@ -31,6 +31,7 @@ jobs:
         with:
           fail: true
             # For parameter description, see https://github.com/lycheeverse/lychee#commandline-parameters
+            # Actions Link address -> https://github.com/lycheeverse/lychee-action
             # -E, --exclude-all-private    Exclude all private IPs from checking.
             # -i, --insecure               Proceed for server connections considered insecure (invalid TLS)
             # -n, --no-progress            Do not show progress bar.