Add decimalplaces property to number field

Added 'decimalplaces' property to the number field in opensign.yaml.

Author: prafull-opensignlabs

docs/docs/API-docs/v1.1/opensign.yaml

@@ -1668,6 +1668,7 @@ paths:
           "readonly": false,
           "default": 0,
           "formula": "",
+          "decimalplaces": 2
         }
         ```