docs(readme): fix numbered list index

Author: utilyre

README.md

@@ -53,7 +53,7 @@ for ; ; <-ticker.C {
 
 	 Take note of `[ADDRESS]`.
 
-3. Run the following. Replace `<n>` with the number of clients you'd like to
+4. Run the following. Replace `<n>` with the number of clients you'd like to
    run and also replace `[ADDRESS]` with the one you took note of in the
    previous step.