[docs] add README for triggers and actions

docs/actions/README.md

@@ -1 +1,23 @@
 # Actions
+
+Actions are executed when their parent Trigger got triggered. 
+They then perform some certain task depending on the specific action.
+Those can vary from shutding down the machine, removing a file or running a bash command.
+**Some Actions may cause permanent damage to the system. This is intended but should be used with caution.**  
+
+Actions can have a ```Stage``` assigned to define in which order they should run.
+The lowest stage is executed first and only when finished the next stage is executed.
+Actions on the same Stage run concurrently.
+
+Actions have the following syntax:
+``` json
+{
+  "type": "SomeAction",
+  "options": { //each action defines its own options
+    "firstOption": "someValue",
+    "Stage": 2 //this (positive) number defines the order of multiple actions
+  }
+}
+```
+
+To get a list of all actions and their options from the commandline run ``` gokill -d ```