Default fieldset short desc to full desc, add single line check

generated/ecs/fields_flat.yml

@@ -817,9 +817,7 @@ event.module:
   level: core
   name: module
   order: 6
-  short: 'Name of the module this data is coming from.
-
-    This information is coming from the modules used in Beats or Logstash.'
+  short: Name of the module this data is coming from.
   type: keyword
 event.original:
   description: 'Raw text message of entire event. Used to demonstrate log integrity.

generated/ecs/fields_nested.yml

@@ -502,6 +502,7 @@ ecs:
   group: 2
   name: ecs
   prefix: ecs.
+  short: Meta-information specific to ECS.
   title: ECS
   type: group
 error:
@@ -1311,6 +1312,7 @@ log:
   group: 2
   name: log
   prefix: log.
+  short: Fields which are specific to log events.
   title: Log
   type: group
 network:

scripts/schema_reader.py

@@ -57,6 +57,10 @@ def schema_cleanup_values(schema):
 def schema_set_default_values(schema):
     schema['type'] = 'group'
     dict_set_default(schema, 'group', 2)
+    dict_set_default(schema, 'short', schema['description'])
+    if "\n" in schema['short']:
+        raise ValueError("Short descriptions must be single line.\nFieldset: {}\n{}".format(schema['name'], schema))
+        # print("Short descriptions must be single line. Fieldset: {}".format(schema['name']))
 
 
 def schema_set_fieldset_prefix(schema):