- added missing categories in keywords.txt
- added dependency of ArduinoJson in library.properties (I didn't add LoRa and PubSubClient but think they should go there as well)
- reformatted paragraph on dependencies as list for better readability
Changed those values to be prevent compiling issues with PlatformIO and also as it is good practice not to use names which easily could collide with other libs.
Also removed a duplicate line from keywords.txt
* keywords.txt (for syntax highlighting), library.properties (for a proper description added
* moved Universal_Sensor_beta to the examples directory
* moved Sensors, FDRS_Sensor and FDRS_Gateway to resources folder. They contain documentation which needs to be kept (to be discussed where to put that later on) but are fully redundant as they are just duplicates of the different sensors / gateways in the examples folder.
