python: add instructions for PyPi packages

bindings/python/README.TXT

@@ -1,3 +1,14 @@
+0. This documentation explains how to install Python binding for Capstone
+   from source. If you want to install it from PyPi package, see the below
+   docs instead:
+
+   - README.pypi-src: How to compile the Capstone core & install binding
+     at the same time from PyPi package "capstone"
+
+   - README.pypi-win: How to install binding for Windows from PyPi package
+     "capstone-windows". Note that this package already has prebuilt core
+	 inside, so no compilation is needed.
+
 1. To install pure Python binding on *nix, run the command below:
 
 		$ sudo make install

bindings/python/README.pypi-src

@@ -1,9 +1,14 @@
-NOTE: This package "capstone" includes source code of the core of Capstone.
+NOTE: This PyPi package "capstone" includes source code of the core of Capstone.
 So installing this would also compile the core with C compiler (either "gcc" or
 "msvc" on Windows).
 
-For Windows, if you do not want to compile the core, install package "capstone_win"
-instead, which already has the prebuilt core inside.
+On Windows, MSVC needs compiler environmental setup, you would need to either
+run "pip install capstone" or "python setup.py install" from "Developer Command
+Prompt".
+
+For Windows, if you do not want to compile the core, try the "capstone-windows"
+package instead, which already has the prebuilt core inside.
+
 --------------------------------------------------------------------------------
 
 Capstone is a disassembly framework with the target of becoming the ultimate

bindings/python/README.pypi-win

@@ -1,6 +1,8 @@
 NOTE: This package includes prebuilt Windows core of Capstone, so no external
 Capstone library is needed.
-To compile from source, see package "capstone".
+
+To compile from source, see PyPi package "capstone" instead.
+
 --------------------------------------------------------------------------------
 
 Capstone is a disassembly framework with the target of becoming the ultimate