nc: Improve title and some examples

pages/common/nc.md

@@ -1,8 +1,8 @@
 # nc
 
-> Reads and writes tcp or udp data.
+> Netcat is a versatile utility for working with TCP or UDP data.
 
-- Listen on a specified port:
+- Listen on a specified port and print any data received:
 
 `nc -l {{port}}`
 
@@ -30,10 +30,10 @@
 
 `nc -q {{timeout}} {{ip_address}}`
 
-- Port scanning:
+- Scan the open ports of a specified host:
 
 `nc -v -z {{ip_address}} {{port}}`
 
-- Proxy and port forwarding:
+- Act as proxy and forward data from a local TCP port to the given remote host:
 
-`nc -l {{port}} | nc {{hostname}} {{port}}`
+`nc -l {{local_port}} | nc {{hostname}} {{remote_port}}`