Add link to http://docs.micropython.org/en/latest/unix/genrst/index.html

Differences.md

@@ -1,4 +1,7 @@
 # Differences to CPython
+
+*NOTE: This page provides high-level overview of differences between MicroPython and CPython. Some specific points may be out of date. Specific list differences are now maintained as a part of MicroPython documentation at http://docs.micropython.org/en/latest/unix/genrst/index.html*
+
 MicroPython does not support the entire python standard library. If a module is missing it will be due to the in-applicability of that module for use in an embedded controller. High memory consumption (e.g. sqlite3) or a lack of a certain required hardware feature (e.g. multiprocessing) are reasons that some modules can not be implemented for some microcontrollers. The full list of standard python libraries can be found here: [Python 3.4 standard lib](https://docs.python.org/3.4/library/index.html)
 
 There are several differences between CPython3 (considered to be a reference implementation of the Python3 language) and MicroPython. These differences are classified into 3 categories, each category having a different status regarding the possibility that items belonging to it will change.