Add link to Github docs

SECURITY.md

@@ -9,4 +9,4 @@
 
 ## Reporting a Vulnerability
 
-If you think you've found a vulnerability, please use the private vulnerability reporting form provided by Github. 
+If you think you've found a vulnerability, please use the [private vulnerability reporting form provided by Github](https://docs.github.com/en/code-security/security-advisories/guidance-on-reporting-and-writing-information-about-vulnerabilities/privately-reporting-a-security-vulnerability#privately-reporting-a-security-vulnerability).