Updating documentation, fixing #503

Author: diemol

README.md

@@ -81,7 +81,16 @@ $ docker run -d -p 4444:4444 -e JAVA_OPTS=-Xmx512m --name selenium-hub selenium/
 You can pass `SE_OPTS` variable with additional commandline parameters for starting a hub or a node.
 
 ``` bash
-$ docker run -d -p 4444:4444 -e SE_OPTS="-debug true" --name selenium-hub selenium/hub:3.2.0-actinium
+$ docker run -d -p 4444:4444 -e SE_OPTS="-debug true" --name selenium-hub selenium/hub:3.4.0-dysprosium
+```
+
+### HUB_PORT_444_TCP_ADDR and HUB_PORT_444_TCP_PORT Selenium Node Configuration options
+
+You can pass `HUB_PORT_444_TCP_ADDR` and `HUB_PORT_444_TCP_PORT` options to provide the hub address to a node when needed.
+
+``` bash
+$ docker run -d -p 4444:4444 -e HUB_PORT_4444_TCP_ADDR=10.10.1.10 -e HUB_PORT_4444_TCP_PORT=4444 \ 
+    --name selenium-hub selenium/hub:3.4.0-dysprosium
 ```
 
 ### PHANTOMJS_OPTS PhantomJS Configuration Options