README: update general description

Author: swistakm

README.md

@@ -1,6 +1,15 @@
 # pyrilla
-Python bindings to gorilla-audio library
 
+pyrilla is a self-contained statically linked binding to
+[gorilla-audio](https://code.google.com/p/gorilla-audio/) library -
+"an attempt to make a free, straightforward, cross-platform, high-level
+software audio mixer that supports playback of both static and streaming
+sounds". Like the original it is intended for video game development.
+
+pyrilla's goal is to provide a python audio package that can be installed
+without any external dependencies with single `pip install pyrilla` command.
+It is built with cython and its API is inspired by part of great but
+unmantained [bacon](https://github.com/aholkner/bacon) game engine.
 
 
 # building