fix(documentationjs): records display with ,

Author: Alexandre Stanislawski

docgen/layouts/mixins/documentationjs/type.pug

@@ -27,8 +27,10 @@ mixin type(t)
     | ]
   else if t.type && t.type === 'RecordType'
     |{
-    for field in t.fields
+    for field, idxField in t.fields
       +type(field)
+      if idxField < t.fields.length - 1
+        |, 
     |}
   else if t.type && t.type === 'FieldType'
     | !{t.key}: