add sql_type options

docs/framework/entities/index.md

@@ -50,6 +50,7 @@ The entityType definition array can contain the following keys:
      * `title` (`ts(string)`)
      * `description` (`ts(string)`)
      * `sql_type` (`string`)
+          e.g 'int', 'int(10) unsigned', 'bigint', 'tinyint', 'varchar(30)', 'datetime', 'decimal'
      * `input_type` (`string`)
      * `data_type` (`string`)
      * `required` (`boolean`)