Update Secure page to include unknown definition

doc/development/integrations/secure.md

@@ -470,6 +470,10 @@ The confidence ranges from `Low` to `Confirmed`, but it can also be `Unknown`,
 `Experimental` or even `Ignore` if the vulnerability is to be ignored.
 Valid values are: `Ignore`, `Unknown`, `Experimental`, `Low`, `Medium`, `High`, or `Confirmed`
 
+`Unknown` values means that data is unavailable to determine it's actual value. Therefore, it may be `high`, `medium`, or `low`,
+and needs to be investigated. We have [provided a chart](../../user/application_security/sast/analyzers.md#analyzers-data)
+of the available SAST Analyzers and what data is currently available.
+
 ### Remediations
 
 The `remediations` field of the report is an array of remediation objects.