fix bugs in the documentation (#1918)

* fix bugs in the documentation

* fix docs error

Author: SunsetWolf

docs/component/workflow.rst

@@ -55,13 +55,16 @@ Below is a typical config file of ``qrun``.
                 n_drop: 5
                 signal: <PRED>
         backtest:
-            limit_threshold: 0.095
+            start_time: 2017-01-01
+            end_time: 2020-08-01
             account: 100000000
             benchmark: *benchmark
-            deal_price: close
-            open_cost: 0.0005
-            close_cost: 0.0015
-            min_cost: 5
+            exchange_kwargs:
+                limit_threshold: 0.095
+                deal_price: close
+                open_cost: 0.0005
+                close_cost: 0.0015
+                min_cost: 5
     task:
         model:
             class: LGBModel

scripts/data_collector/yahoo/README.md

@@ -50,12 +50,6 @@ pip install -r requirements.txt
     python scripts/get_data.py qlib_data --target_dir ~/.qlib/qlib_data/cn_data_1min --region cn --interval 1min
     # us 1d
     python scripts/get_data.py qlib_data --target_dir ~/.qlib/qlib_data/us_data --region us --interval 1d
-    # us 1min
-    python scripts/get_data.py qlib_data --target_dir ~/.qlib/qlib_data/us_data_1min --region us --interval 1min
-    # in 1d
-    python scripts/get_data.py qlib_data --target_dir ~/.qlib/qlib_data/in_data --region in --interval 1d
-    # in 1min
-    python scripts/get_data.py qlib_data --target_dir ~/.qlib/qlib_data/in_data_1min --region in --interval 1min
     ```
 
 ### Collector *YahooFinance* data to qlib