added note for known typo (#2369)

* added note for known typo

* fixed comment structure

* fixed comment style

* dot

specification/indices/_types/DataStream.ts

@@ -33,6 +33,8 @@ enum ManagedBy {
   /** @codegen_name ilm */
   'Index Lifecycle Management',
   /** @codegen_name datastream */
+  // This should have been written with capital letters, it's a known typo and should not be corrected,
+  // since the test cases have already been written.
   'Data stream lifecycle',
   /** @codegen_name unmanaged */
   'Unmanaged'
@@ -42,7 +44,8 @@ export class DataStream {
   /**
    * Custom metadata for the stream, copied from the `_meta` object of the stream’s matching index template.
    * If empty, the response omits this property.
-   * @doc_id mapping-meta-field */
+   * @doc_id mapping-meta-field
+   */
   _meta?: Metadata
   /**
    *  If `true`, the data stream allows custom routing on write request.