readme: Update markdown format

Remove backslash

Add note that all domains should point to the same host (will be assumed
later)

Author: yarrick

README.md

@@ -296,9 +296,10 @@ DNSCACHE_LEN is still advised, preferably 2 or higher, however you can also
 undefine it to save a few more kilobytes.
 
 One iodine server can handle multiple domains. Set up different NS records
-on the same domain all pointing to the same host, and use `\*.mydomain.com`
+on the same domain all pointing to the same host, and use `*.mydomain.com`
 as topdomain argument. iodine will accept tunnel traffic for all domains matching that
-pattern.
+pattern. All tunnels using the same server should use the same hostname for
+all NS delegations.
 
 
 PERFORMANCE