Created Custom Background Task (markdown)

Custom-Background-Task.md

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+You can extend CraftBeerPi with custom background task. Below you will find a basic example where the method gets invoked every secons
+
+```
+from modules import cbpi, 
+
+@cbpi.backgroundtask(key="my_task", interval=1)
+def my_custom_background_task():
+    # YOUR CODE GOES HERE
+    pass
+        
+```
+
+@cbpi.backgroundtask Parameter
+* key = String value free to choose but must be unique in CraftBeerPi system
+* interval = float value in which interval the method is invoked. ie: 0.1 = 100ms 1=1sec