Update README.md

Author: lefticus

README.md

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+# NOTE: This Project Is Archived
+
+All efforts to maintain "Best Practices" CMake templates are being merged into https://github.com/cpp-best-practices/cmake_template
+
+***Important*** the new cmake_template is simplified in many ways to make it more maintainable, and the goal will be to always keep it simple.
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 # gui_starter_template
 
 [![ci](https://github.com/cpp-best-practices/gui_starter_template/actions/workflows/ci.yml/badge.svg)](https://github.com/cpp-best-practices/gui_starter_template/actions/workflows/ci.yml)