Add flag to readme

Signed-off-by: Jakub Štiller <[email protected]>
Signed-off-by: Jakub Štiller <[email protected]>

Author: Delorien84

README.md

@@ -153,6 +153,9 @@ This will build the docker image as `prometheuscommunity/postgres_exporter:${bra
 * `[no-]collector.stat_statements.include_query`
   Enable selecting statement query together with queryId. (default: disabled)
 
+* `--collector.stat_statements.query_length`
+  Maximum length of the statement text. Default is 120.
+
 * `[no-]collector.stat_user_tables`
   Enable the `stat_user_tables` collector (default: enabled).