Update masscan.8.markdown

    consume a lot of memory on fast scans. While the code may handle millions of 

    open TCP connections, you may not have enough memory for that.

  * `--hello-file[<port>] <filename>`: send the contents of the file once the 

    TCP connection has been established with the given port. Requires that

    `--banners` also be set. Heuristics will be performed on the reponse in

    an attempt to discover what protocol, so HTTP responses will be parsed

    differently than other protocols.

  * `--hello-string[<port>] <base64>`: same as `--hello-file` except that the

    contents of the BASE64 encoded string are decoded, then used as the hello

    string that greets the server.

## CONFIGURATION FILE FORMAT