Add CVSSv3.1 Qualitative Severity Rating scoring system

Signed-off-by: Shivam Sandbhor <shivam.sandbhor@gmail.com>

Author: sbs2001

vulnerabilities/severity_systems.py

@@ -74,5 +74,11 @@ def as_score(self, value):
         identifier="avgs",
         name="Archlinux Vulnerability Group Severity",
         url="https://wiki.archlinux.org/index.php/Bug_reporting_guidelines#Severity"
+    ),
+    "cvssv3.1_qr": ScoringSystem(
+        identifier="cvssv3.1_qr",
+        name="CVSSv3.1 Qualitative Severity Rating",
+        url="https://www.first.org/cvss/specification-document",
+        notes="A textual interpretation of severity. Has values like HIGH, MODERATE etc"
     )
 }