Update: README.md

README.md

 
 ```Shell
 # Activate the choppy environment
-open-choppy-env
+$open-choppy-env
 
 # Install the APP
-choppy install YaqingLiu/variant-calling-latest [-f]
+$choppy install YaqingLiu/variant-calling-latest [-f]
 
 # List the parameters
-choppy samples YaqingLiu/variant-calling-latest [--no-default]
+$choppy samples YaqingLiu/variant-calling-latest [--no-default]
 
 # Submit you task with the `samples.csv file` and `project name`
-choppy batch YaqingLiu/variant-calling-latest samples.csv -p Project [-l project:Label]
+$choppy batch YaqingLiu/variant-calling-latest samples.csv -p Project [-l project:Label]
 
 # Query the status of all tasks in the project
-choppy query -L Label | grep "status"
+$choppy query -L Label | grep "status"
 ```
 
-**Please note**: The `defaults` can be forcibly replaced by the settings in `samples.csv`. Therefore, there is no need to contact me over this issue.
+**Please note:** The `defaults` can be forcibly replaced by the settings in `samples.csv`. Therefore, there is no need to contact me over this issue.
 
 The parameters that must need contains: sample_id,normal_fastq_1,normal_fastq_2,tumor_fastq_1,tumor_fastq_2