credits: add Credits.rtf file

Necessary to generate About screen

Refs #69161

Change-Id: I23786447caf46a096aadbc083d3dd2287c6552b5
diff --git a/MainMenu.xib b/MainMenu.xib
index 1ad9425..a7263c7 100644
--- a/MainMenu.xib
+++ b/MainMenu.xib
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <archive type="com.apple.InterfaceBuilder3.Cocoa.XIB" version="8.00">
 	<data>
-		<int key="IBDocument.SystemTarget">1090</int>
+		<int key="IBDocument.SystemTarget">101000</int>
 		<string key="IBDocument.SystemVersion">13F34</string>
 		<string key="IBDocument.InterfaceBuilderVersion">6254</string>
 		<string key="IBDocument.AppKitVersion">1265.21</string>