website: add the security page

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>

Author: AkihiroSuda

website/content/en/docs/security/_index.md

@@ -0,0 +1,16 @@
+---
+title: Security
+weight: 350
+---
+
+## Security model
+
+See <https://github.com/cncf/tag-security/blob/main/community/assessments/projects/lima/self-assessment.md>.
+
+## Reporting vulnerabilities
+
+See <https://github.com/lima-vm/.github/blob/main/SECURITY.md>.
+
+## Past vulnerabilities
+
+See <https://github.com/lima-vm/lima/security>.