Update workflow.rst

Corrected an identation problem on the configuration.yaml file.

Author: lbaiao

docs/component/workflow.rst

@@ -90,12 +90,12 @@ Below is a typical config file of ``qrun``.
                     test: [2017-01-01, 2020-08-01]
         record: 
             - class: SignalRecord
-            module_path: qlib.workflow.record_temp
-            kwargs: {}
+                module_path: qlib.workflow.record_temp
+                kwargs: {}
             - class: PortAnaRecord
-            module_path: qlib.workflow.record_temp
-            kwargs: 
-                config: *port_analysis_config
+                module_path: qlib.workflow.record_temp
+                kwargs: 
+                    config: *port_analysis_config
 
 After saving the config into `configuration.yaml`, users could start the workflow and test their ideas with a single command below.