Add file header template for new files (#487)

Author: laevandus

StreamChatSwiftUI.xcodeproj/xcshareddata/IDETemplateMacros.plist

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>FILEHEADER</key>
+	<string>
+// Copyright © ___YEAR___ Stream.io Inc. All rights reserved.
+//</string>
+</dict>
+</plist>