Update OS X installer ReadMe for 360b2.

Mac/BuildScript/resources/ReadMe.rtf

-{\rtf1\ansi\ansicpg1252\cocoartf1504
+{\rtf1\ansi\ansicpg1252\cocoartf1504\cocoasubrtf390
 {\fonttbl\f0\fswiss\fcharset0 Helvetica;\f1\fmodern\fcharset0 CourierNewPSMT;}
 {\colortbl;\red255\green255\blue255;}
 {\*\expandedcolortbl;\csgray\c100000;}
@@ -43,7 +43,7 @@ Certificate verification and OpenSSL\
 \f1 certifi
 \f0  package ({\field{\*\fldinst{HYPERLINK "https://pypi.python.org/pypi/certifi"}}{\fldrslt https://pypi.python.org/pypi/certifi}}).  If you choose to use 
 \f1 certifi
-\f0 , you should consider subscribing to the{\field{\*\fldinst{HYPERLINK "https://certifi.io/en/latest/"}}{\fldrslt  project's email update service}} to be notified when the certificate bundle is updated.\
+\f0 , you should consider subscribing to the{\field{\*\fldinst{HYPERLINK "https://certifi.io/en/latest/"}}{\fldrslt  project's email update service}} to be notified when the certificate bundle is updated.  More options will be provided prior to the final release of 3.6.0.\
 \
 The bundled 
 \f1 pip
@@ -58,7 +58,7 @@ To use IDLE or other programs that use the Tkinter graphical user interface tool
 \i Tcl/Tk
 \i0  frameworks.  Visit {\field{\*\fldinst{HYPERLINK "https://www.python.org/download/mac/tcltk/"}}{\fldrslt https://www.python.org/download/mac/tcltk/}} for current information about supported and recommended versions of 
 \i Tcl/Tk
-\i0  for this version of Python and of Mac OS X.  For the initial alpha releases of Python 3.6, the installer is still linked with Tcl/Tk 8.5; this will change prior to the beta 2 release of 3.6.0.\
+\i0  for this version of Python and of Mac OS X.  For the initial preview releases of Python 3.6, the installer is still linked with Tcl/Tk 8.5; this will likely change prior to the final release of 3.6.0.\
 
 \b \ul \
 Other changes\