add namespace pattern and update examples

Author: ahouseholder

data/schema/v2/Decision_Point_Value_Selection-2-0-0.schema.json

@@ -8,9 +8,12 @@
           "examples": [
             "ssvc",
             "cisa",
-            "certcc"
+            "x_private-test",
+            "ssvc/de-DE/reference-arch-1"
           ],
+          "maxLength": 1000,
           "minLength": 3,
+          "pattern": "^(?=.{3,1000}$)(x_)?[a-z0-9]{3}([/.-]?[a-z0-9]+){0,997}$$",
           "title": "Namespace",
           "type": "string"
         },