docs: link contribution guide - #2

The 'client-id' (or deprecated 'app-id') input must be set to a non-empty string. If using a secret or variable, ensure it is available in this workflow context.

On November 2, 2026, GitHub will restrict `pull_request_target` on public repositories by default. To continue allowing the event trigger, configure an Actions policy. Learn more: https://gh.io/securely-using-pull_request_target#default-policy-for-pull_request_target