fix: doc minor (thulab#480)

Author: niebayes

README.md

@@ -86,11 +86,6 @@ git checkout [branch name]
 
 Use the following command to complete the construction of iot-benchmark through Maven:
 
-```
-mvn clean package -Dmaven.test.skip=true
-```
-This command will compile the core module of iot-benchmark and all other related databases.hmark through Maven:
-
 ```
 mvn clean package -Dmaven.test.skip=true
 ```