Permanently archive the project

The project is dead and should not be used anymore.

Author: PowerKiKi

README.md

@@ -1,11 +1,8 @@
-# PHPExcel - DEPRECATED
+# PHPExcel - DEAD
 
-PHPExcel last version, 1.8.1, was released in 2015. The project is no longer maintained and 
-should not be used anymore.
+PHPExcel last version, 1.8.1, was released in 2015. The project was officially deprecated in 2017 and permanently archived in 2019.
 
-All **users should migrate** to its direct successor [PhpSpreadsheet](https://github.com/PHPOffice/PhpSpreadsheet), or another alternative.
-
-In a few months, the GitHub project will be marked as archived, so everything will be read-only.
+The project has not be maintained for years and must not be used anymore. **All users must migrate** to its direct successor [PhpSpreadsheet](https://github.com/PHPOffice/PhpSpreadsheet), or another alternative.
 
 ## License