Remove misleading explanation of old genstage behaviour (#212)

Author: LostKobrakai

lib/consumer_supervisor.ex

@@ -23,12 +23,8 @@ defmodule ConsumerSupervisor do
   Let's define a GenStage consumer as a `ConsumerSupervisor` that subscribes
   to a producer named `Producer` and starts a new process for each event
   received from the producer. Each new process will be started by calling
-  `Printer.start_link/2`, which simply starts a task that will print the
-  incoming event to the terminal. `Printer.start_link/2` is called because
-  the `Printer` child specification defaults to starting a `Printer` with
-  `Printer.start_link([])` (see the documentation for `Supervisor`)
-  but the `ConsumerSupervisor` adds the event as another argument when starting
-  the child, effectively calling `Printer.start_link([], event)`.
+  `Printer.start_link/1`, which simply starts a task that will print the
+  incoming event to the terminal. 
 
       defmodule Consumer do
         use ConsumerSupervisor