update docs

README.md

@@ -4,6 +4,11 @@ Bare-bones MQTT CLI for Mac and Linux.
 
 This project is a personal learning exercise, for diving into MQTT internals and network programming.  On the small chance that you're considering actually using this client....just use one of the real ones listed below.
 
+## Publish to a topic
+```
+mqtt pub -t hello/topic -a localhost:1883 -c clientId '{"hello": "world"}'
+```
+
 ```
 Usage: mqtt pub [-v] -t <topic> -a <address> -c <clientId> <message>
 Options:
@@ -14,13 +19,23 @@ Options:
   -h, --help                    Show this help message
 ```
 
-## Publish to a topic
+## Subscribe to a topic
+
+> :alert: Work in progress. Subscribe request is sent, but still need to actually listen for payloads.
+
 ```
-mqtt pub -t hello/topic -a localhost:1883 -c clientId '{"hello": "world"}'
+mqtt sub -t hello/topic -a localhost:1883 -c clientId
 ```
 
-## Subscribe to a topic
-WIP
+```
+Usage: mqtt sub [-v] -t <topic> -a <address> -c <clientId>
+Options:
+  -t, --topic <topic>           Specify the topic to publish to (required)
+  -a, --address <address>       <host>[:<port>] address to connect to (required)
+  -c, --client-id <client id>   Client identifier
+  -v, --verbose                 Enable verbose output
+  -h, --help                    Show this help message
+```
 
 ## Features