Clean up code comments and docstrings (#318)

Signed-off-by: rany <rany2@riseup.net>

src/edge_tts/communicate.py

@@ -1,6 +1,5 @@
-"""
-Communicate package.
-"""
+"""Communicate with the service. Only the Communicate class should be used by
+end-users. The other classes and functions are for internal use only."""
 
 import asyncio
 import concurrent.futures