added Installation section

Author: gorgitko

README.md

@@ -1,5 +1,10 @@
 # valve-keyvalues-python
-Python class for manipulation with Valve KeyValues files (VDF format). Provides parsing of VDF files to object with dict interface, editing of this object keys and values and writing of any object with dict interface to VDF file format.
+Python class for manipulation with Valve KeyValues files (VDF format). Provides the parsing of VDF files to objects with dict interface, editing of this object keys and values and writing of any object with dict interface to VDF file format.
+
+# Installation
+Just copy the `valve-keyvalues-python` folder wherever you need, for example to your Python's site-packages: `<Python>/Lib/site-packages/` and then inside your program import the class by `from valve-keyvalues-python import KeyValues`
+
+**Requires Python 3!**
 
 # Usage