Add release badge

Author: Pavel Dmytrenko

README.md

@@ -1,5 +1,6 @@
 [![GitHub license](https://img.shields.io/github/license/AnchorFree/vmbackup-sidecar.svg)](https://github.com/AnchorFree/vmbackup-sidecar/blob/master/LICENSE)
 [![Go Report](https://goreportcard.com/badge/github.com/AnchorFree/vmbackup-sidecar)](https://goreportcard.com/report/github.com/AnchorFree/vmbackup-sidecar)
+![GitHub release (latest by date including pre-releases)](https://img.shields.io/github/v/release/AnchorFree/vmbackup-sidecar?include_prereleases)
 
 vmbackup-sidecar
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