Update README.md

Adding extra info to ReadMe

Author: redcubie

README.md

@@ -1,2 +1,9 @@
 # pyBA63
 Python library for using Wincor Nixdorf BA63 VFD display over COM port
+# Installation
+pyBA63 requires `pyserial` and [Python](http://www.python.org) to work.
+It has been tested with Python 3.  
+Windows:
+`py -m pip install pyserial`  
+Linux:
+`pip install pyserial`