docs/differences: Clarify the differences are against Python 3.4.
@@ -4,6 +4,7 @@ MicroPython differences from CPython
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The operations listed in this section produce conflicting results in MicroPython when compared to standard Python.
+MicroPython implements Python 3.4 and some select features of Python 3.5.
.. toctree::
:maxdepth: 2
