Update README.md

README.md

@@ -1,5 +1,8 @@
+#### Introduction
 The bcftools-merge is used to merge VCF files into a singe VCF.
+
 A common scenario is that after generating all VCF files you want to include in the panel, you can use bcftools-merge to merge them into a single Panel of Normal VCF.
+
 #### Usage
 ```bash
 # Enter the Choppy work environment
@@ -11,6 +14,7 @@ touch samples.json
 # Submit your job
 choppy batch YaqingLiu/bcftools-merge-latest samples.json -p project_name
 ```
+
 #### Input File
 Input file `samples.json` should be in the form of json.
 For example: