feat: adding a bind shell example with more stuff

adding a bind shell that can allow for more practice with future
features such as multiple transports, encryption, transferring files,
and a more robust client interface

pcap-sys/src/lib.rs

@@ -146,6 +146,7 @@ impl<T: State> Drop for Interface<T> {
 }
 
 unsafe impl<T: State> Send for Interface<T> {}
+unsafe impl<T: State> Sync for Interface<T> {}
 
 impl<T: State> Interface<T> {
     pub fn new(name: &str) -> error::Result<Interface<DevDisabled>> {