Added changes on non-async query, and improved async ones

Author: ivancea

specification/esql/async_query/AsyncQueryRequest.ts

@@ -61,6 +61,8 @@ export interface Request extends RequestBase {
      * A short version of the Accept header, for example `json` or `yaml`.
      * 
      * `csv`, `tsv`, and `txt` formats will return results in a tabular format, excluding other metadata fields from the response.
+     * 
+     * For async requests, nothing will be returned if the async query doesn't finish within the timeout.
      */
     format?: EsqlFormat
   }

specification/esql/query/QueryRequest.ts

@@ -43,6 +43,8 @@ export interface Request extends RequestBase {
   query_parameters: {
     /**
      * A short version of the Accept header, e.g. json, yaml.
+     * 
+     * `csv`, `tsv`, and `txt` formats will return results in a tabular format, excluding other metadata fields from the response.
      */
     format?: EsqlFormat
     /**