Added related/cve:'s listed in advisory

Author: jasnow

gems/nokogiri/GHSA-7rrm-v45f-jp64.yml

@@ -119,3 +119,13 @@ description: |
 cvss_v3: 7.5
 patched_versions:
   - ">= 1.11.4"
+related:
+  cve:
+    - 2019-20388
+    - 2020-24977
+    - 2020-7595
+    - 2021-3516
+    - 2021-3517
+    - 2021-3518
+    - 2021-3537
+    - 2021-3541