README: show the libmatroska package support of many Linux distros

Author: robUx4

README.md

@@ -41,3 +41,7 @@ following additional `cmake` options are supported:
 ## Code of conduct
 
 Please note that this project is released with a [Contributor Code of Conduct](CODE_OF_CONDUCT.md). By participating in this project you agree to abide by its terms.
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+# Packaging status
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+[![Packaging status](https://repology.org/badge/vertical-allrepos/libmatroska.svg?columns=3&header=libmatroska&exclude_unsupported=1)](https://repology.org/project/libmatroska/versions)