fastq extension added

README.md

@@ -57,7 +57,7 @@ Once you have all the files, edit the config.json file with your raw fastq and o
 the fastq files must be located in the DATA folder and with gz format.
 In your terminal use this command 
 ```shell
-gzip SRR5625858
+gzip SRR5625858.fastq
 ```
 
 At this point you have all the data needed to run the pipeline.