use markdown syntax in README

README.md

@@ -6,12 +6,15 @@ Some scripts to create and renew all your certificates, and concatenate fullchai
 Create a certificate with let's encrypt, then concatenate fullchain.pem and privkey.pem, then store the certificate in haproxy given path.
 
 Usage :  
+```
 ./create-certificate domain.tld >> /var/log/create-certificate.log
+```
 
 ## How to renew certificates
 **Renew all certificate known by let's encrypt !**
 
 Usage :  
+```
 ./renew-certificate >> /var/log/renew-certificates.log
-
+```