Minor updates to the macOS installer screens for 3.8.0b2 (GH-14501)

Mac/BuildScript/resources/ReadMe.rtf

-{\rtf1\ansi\ansicpg1252\cocoartf1671\cocoasubrtf200
+{\rtf1\ansi\ansicpg1252\cocoartf1671\cocoasubrtf500
 {\fonttbl\f0\fswiss\fcharset0 Helvetica;\f1\fswiss\fcharset0 Helvetica-Bold;\f2\fswiss\fcharset0 Helvetica-Oblique;
 \f3\fmodern\fcharset0 CourierNewPSMT;}
 {\colortbl;\red255\green255\blue255;}
@@ -8,12 +8,18 @@
 
 \f0\fs24 \cf0 This package will install Python $FULL_VERSION for macOS $MACOSX_DEPLOYMENT_TARGET for the following architecture(s): $ARCHITECTURES.\
 \
+\pard\tx720\tx1440\tx2160\tx2880\tx3600\tx4320\tx5040\tx5760\tx6480\tx7200\tx7920\tx8640\partightenfactor0
+
+\f1\b \cf0 NOTE: 
+\f0\b0 This is a beta test preview of Python 3.8.0, the next feature release of Python 3.8.  It is not intended for production use.\
+\pard\tx720\tx1440\tx2160\tx2880\tx3600\tx4320\tx5040\tx5760\tx6480\tx7200\tx7920\tx8640\pardirnatural\partightenfactor0
+\cf0 \
 \pard\tx720\tx1440\tx2160\tx2880\tx3600\tx4320\tx5040\tx5760\tx6480\tx7200\tx7920\tx8640\pardirnatural\partightenfactor0
 
 \f1\b \cf0 \ul \ulc0 Certificate verification and OpenSSL\
 
 \f0\b0 \ulnone \
-This package includes its own private copy of OpenSSL 1.1.0.   The trust certificates in system and user keychains managed by the 
+This package includes its own private copy of OpenSSL 1.1.1.   The trust certificates in system and user keychains managed by the 
 \f2\i Keychain Access 
 \f0\i0 application and the 
 \f2\i security

Mac/BuildScript/resources/Welcome.rtf

-{\rtf1\ansi\ansicpg1252\cocoartf1671\cocoasubrtf200
-\cocoascreenfonts1{\fonttbl\f0\fswiss\fcharset0 Helvetica;\f1\fswiss\fcharset0 Helvetica-Bold;}
+{\rtf1\ansi\ansicpg1252\cocoartf1671\cocoasubrtf500
+\cocoascreenfonts1{\fonttbl\f0\fswiss\fcharset0 Helvetica;\f1\fswiss\fcharset0 Helvetica-Bold;\f2\fmodern\fcharset0 CourierNewPSMT;
+}
 {\colortbl;\red255\green255\blue255;}
 {\*\expandedcolortbl;;}
 \paperw11905\paperh16837\margl1440\margr1440\vieww12200\viewh10880\viewkind0
@@ -17,7 +18,11 @@
 \f1\b IDLE
 \f0\b0 .\
 \
+At the end of this install, click on 
+\f2 Install Certificates
+\f0  for SSL root certificates\
+\
 
 \f1\b NOTE: 
-\f0\b0 This is an alpha test preview of Python 3.8.0, the next feature release of Python 3.8.  It is not intended for production use.\
+\f0\b0 This is a beta test preview of Python 3.8.0, the next feature release of Python 3.8.  It is not intended for production use.\
 }
\ No newline at end of file