Add warning about Qukeys/SpaceCadet compatibilty to AutoShift docs

Signed-off-by: Michael Richters <gedankenexperimenter@gmail.com>

plugins/Kaleidoscope-AutoShift/README.md

@@ -78,6 +78,20 @@ As you can see, this method takes a `Key` as its input and returns either `true`
 (for keys eligible to be auto-shifted) or `false` (for keys AutoShift will leave
 alone).
 
+## Plugin compatibility
+
+If you're using AutoShift in a sketch that also includes the Qukeys and/or
+SpaceCadet plugins, make sure to register AutoShift after those other plugins in
+order to prevent auto-shifts from getting clobbered.  The recommended order is
+as follows:
+
+```c++
+KALEIDOSCOPE_INIT_PLUGINS(Qukeys, SpaceCadet, AutoShift)
+```
+
+It's not generally recommended to use AutoShift on the same key(s) handled by
+either Qukeys or SpaceCadet, as this can result in confusing behaviour.
+
 ## Further reading
 
 Starting from the [example][plugin:example] is the recommended way of getting