Update 'Policy' to 'Security policy', to reflect wording visible in UI

See what is visible in the UI (left sidebar, under Reporting): https://github.com/user-attachments/assets/0141a27b-6def-4341-88c2-6f7dcb2f045b

Author: nicolas-raoul

content/code-security/how-tos/report-and-fix-vulnerabilities/configure-vulnerability-reporting/adding-a-security-policy-to-your-repository.md

@@ -18,7 +18,7 @@ category:
 
 {% data reusables.repositories.navigate-to-repo %}
 {% data reusables.repositories.sidebar-security %}
-1. In the left sidebar, under "Reporting", click **{% octicon "law" aria-hidden="true" aria-label="law" %} Policy**.
+1. In the left sidebar, under "Reporting", click **{% octicon "law" aria-hidden="true" aria-label="law" %} Security policy**.
 1. Click **Start setup**.
 1. In the new `SECURITY.md` file, add information about supported versions of your project and how to report a vulnerability.
 {% data reusables.files.write_commit_message %}