Update file UNIX_HPC_exercise_instructions.md

exercises/UNIX_HPC_exercise_instructions.md

@@ -118,7 +118,7 @@
    
 3. **Create a new directory called `intro_to_unix`**. 
    
-4. **Move the fasta file `ompA_short_ref.fasta` into the new directory.** 
+4. **Move the fasta file `ompA_ref_short.fasta` into the new directory.** 
    * Look at the content of `intro_to_unix` without entering the directory. 
 
 5. **Move the rest of the fasta files**, but NOT the zip archive into `intro_to_unix`.