Update README.md

Link to Discord
Remove "Supported Devices" list, not complete and hard to keep updated
Remove info about developing the plugin outside of Signal K, no longer relavent .

README.md

@@ -9,20 +9,12 @@ possible to run [Venus OS](https://github.com/victronenergy/venus/wiki) on a
 [RaspberryPi2 or 3](https://github.com/victronenergy/venus/wiki/raspberrypi-install-venus-image),
 for example.
 
-Supported Victron products:
-- Inverter/Chargers: Multis, Quattros
-- Battery Monitors: any type that is supported by Venus. For example the BMV-700 series, or the
-Lynx Shunt VE.Can, as well as various integrated Lithium battery systems.
-- Solar Chargers: both the types with a VE.Direct and the types with a VE.Can connection
-- Tank senders: the resistive inputs on the Venus GX, as well as a tank sender connected to Venus
-over N2K
-
 Know that there is also a version of Venus OS with signalk-server, and this plug-in pre-installed.
 In which case you don't need to self install or configure this plugin. See
 [Venus OS large](https://www.victronenergy.com/live/venus-os:large).
 
 ## Support
-Use the #victron channel on the [Signal K Slack](http://slack-invite.signalk.org/).
+Use the #victron channel on [Discord](https://discord.gg/uuZrwz4dCS).
 
 ## Plugin installation & configuration
 Installing is simple. The plugin is available in the signalk app store. Simply click to install.
@@ -42,27 +34,3 @@ on the ethernet/wifi network. You should use SSL if GX-device is not on the loca
 When using option B or C go enter the hostname or ipaddress of the Venus device in the plugin configuration.
 
 Also ensure that MQTT is turned on in the GX-devices Services Settings.
-
-## Test harness
-
-To see data, without having actual Victron or other Venus compatible hardware setup,
-get and run below explained Dummy data script. Or, clone
-[dbus-recorder](https://github.com/victronenergy/dbus-recorder) and run play.sh.
-
-Note that using the test harness could cause for some errors during init, as it
-doesn't support doing a GetValue on the root item (/).
-
-## How to develop this plugin outside of Signal K
-
-First run `npm install`.
-
-Use ./demo.sh to run the code with full debug logging and the produced delta
-serialised to stdout.
-
-When not tested on an actual Venus device, there will be no output since there
-is no data coming in. Use a dummy data script to test / develop on a pc:
-
-https://gist.github.com/mpvader/94672c05d68bb6762859ba70240ea887
-
-dbus-listener.py is an example of how similar data would be read in Python. It
-is not required to use the plugin.