add setup script to build an msi windows installer

README.md

@@ -115,6 +115,14 @@ python web.py --identity-base64 "GCN6mMhVemdNIK/fw97C1zvU17qjQPFTXRBotVckeGmoOwQ
 
 > NOTE: this is a randomly generated identity for example purposes. Do not use it, it has been leaked!
 
+# Build from Source
+
+You can build a standalone Windows Installer `.msi` with the following command;
+
+```
+python setup.py bdist_msi
+```
+
 ## TODO
 
 - [ ] conversations/contacts list ui with unread indicators