add custom field "stringtemplate"

models/customFields.js

@@ -29,6 +29,7 @@ CustomFields.attachSchema(
         'dropdown',
         'checkbox',
         'currency',
+        'stringtemplate',
       ],
     },
     settings: {
@@ -64,6 +65,10 @@ CustomFields.attachSchema(
         },
       }),
     },
+    'settings.stringtemplateFormat': {
+      type: String,
+      optional: true,
+    },
     showOnCard: {
       /**
        * should we show on the cards this custom field