[DOC] Add support methods and contributors (#646)

* [DOC] Add support methods and contributors link

docs/participate/support.md

@@ -0,0 +1,6 @@
+If you like the project and/or used it please consider supporting it! It can be done in different ways:
+* Helping other users in the [community](https://community.openmqttgateway.com)
+* [Contribute](development) to the [code](https://github.com/1technophile/OpenMQTTGateway) or the [documentation](https://docs.openmqttgateway.com)
+* Buy devices or parts from the [devices list](https://docs.google.com/spreadsheets/u/1/d/1_5fQjAixzRtepkykmL-3uN3G5bLfQ0zMajM9OBZ1bx0/edit#gid=2126158079=), the devices and parts linked use affiliated links.
+* Donate or sponsor the project [developpers](https://github.com/1technophile/OpenMQTTGateway/graphs/contributors)
+* Make a video or a blog article about what you have done with [OpenMQTTGateway](https://docs.openmqttgateway.com)