[docs] add README for triggers and actions

docs/triggers/README.md

@@ -1 +1,21 @@
 # Triggers
+
+Triggers wait for certain events and execute the actions defined for them.
+There are different Triggers for different use cases.
+For example ```UsbDisconnect``` is triggered when a certain Usb Drive is unplugged.
+If you want your actions to be triggered when an ethernet cable is pulled use ```EthernetDisconnect``` instead.
+
+Triggers have the following syntax:
+``` json
+{
+  "type": "SomeTrigger",
+  "name": "MyFirstTrigger",
+  "options": { //each trigger defines its own options
+    "firstOption": 23,
+    "secondOption": "foo"
+  },
+  "actions": [] //list actions that should be executed here
+}
+```
+
+To get a list of all triggers and their options from the commandline run ```gokill -d```