Update readme.md

Author: mengluli-web

readme.md

@@ -44,6 +44,7 @@ For **new host/phage**, users can download the DNA and protein sequences from th
 **Note:** 
 
 In code/compute_dna_features.py, users need to install the iLearn tool [https://ilearn.erc.monash.edu/ or https://github.com/Superzchen/iLearn] and prepare .fasta file, this file is DNA sequences of all phages/hosts. (when you use iLearn to compute the DNA features, you should set the parameters k of Kmer and RCKmer as 3, not 2.)
+
 In code/compute_protein_features.py, users need to prepare a .gb file of every phage/host.  
 
 Then users use generate_data.py and main.py to predict PHI.