add extra parameters info

README.md

@@ -49,7 +49,13 @@ Add one of the tags, if required, to the linuxserver/tvheadend line of the run/c
 
 If you use IPTV, SAT>IP or HDHomeRun, you need to create the container with --net=host and remove the -p flags. This is because of a limitation in docker and multicast.
 
-**Parameters**
+## Parameters
+
+`The parameters are split into two halves, separated by a colon, the left hand side representing the host and the right the container side. 
+For example with a port -p external:internal - what this shows is the port mapping from internal to external of the container.
+So -p 8080:80 would expose port 80 from inside the container to be accessible from the host's IP on port 8080
+http://192.168.x.x:8080 would show you what's running INSIDE the container on port 80.`
+
 
 * `-p 1234` - the port(s)
 * `-v /config` - explain what lives here