Update macOS installer Welcome and ReadMe files for 3.7.0. (GH-7653)

diff --git a/Mac/BuildScript/resources/Welcome.rtf b/Mac/BuildScript/resources/Welcome.rtf
index 1aa3819..8e1847e 100644
--- a/Mac/BuildScript/resources/Welcome.rtf
+++ b/Mac/BuildScript/resources/Welcome.rtf
@@ -1,4 +1,4 @@
-{\rtf1\ansi\ansicpg1252\cocoartf1561\cocoasubrtf200
+{\rtf1\ansi\ansicpg1252\cocoartf1561\cocoasubrtf400
 \cocoascreenfonts1{\fonttbl\f0\fswiss\fcharset0 Helvetica;}
 {\colortbl;\red255\green255\blue255;}
 {\*\expandedcolortbl;;}
@@ -18,10 +18,6 @@
 \b0 .\
 \
 
-\b NOTE:
-\b0   This is an beta preview of the next feature release of Python 3.  New features may change substantially or be deleted prior to the final code freeze.\
-\
-
-\b NEW in 3.7.0b1: 
-\b0 two installer variants (10.9+ 64-bit-only, 10.6+ 64-/32-bit), built-in Tcl/Tk 8.6 support (no additional third-party downloads!), OpenSSL 1.1.0g, and more!\
+\b NEW in 3.7.0: 
+\b0 two installer variants (10.9+ 64-bit-only, 10.6+ 64-/32-bit), built-in Tcl/Tk 8.6 support (no additional third-party downloads!), OpenSSL 1.1.0, and more!\
 }
\ No newline at end of file