Update README.md

Adding explicit note for additional libraries location to run demo code.

Author: Toni Klopfenstein

README.md

@@ -8,6 +8,8 @@ Weather Shield is an Arduino shield that gathers relative humidity, barometric p
 
 Weather Shield is an open source hardware project.
 
+**NOTE**: You will need to install additional libraries to work with the example sketch for this board. Please check the [MPL3115A2 Breakout Repo](https://github.com/sparkfun/MPL3115A2_Breakout) and the [HTU21D Breakout Repo](https://github.com/sparkfun/HTU21D_Breakout) for the required libraries.  
+
 Repository Contents
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@@ -21,4 +23,4 @@ License Information
 
 The hardware design and firmware are released under [Creative Commons Share-alike 3.0](http://creativecommons.org/licenses/by-sa/3.0/).  
 All other code is public domain but you buy me a beer if you use this and we meet someday ([Beerware license](http://en.wikipedia.org/wiki/Beerware)).
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