doc: added (Sonatype Nexus) snapshots shields

README.md

@@ -4,6 +4,7 @@ SQLDump
 
 [![GNU Lesser General Public License, v3](https://img.shields.io/github/license/tbrugz/sqldump.svg?label=License&color=blue)](LICENSE)
 [![Maven Central](https://img.shields.io/maven-central/v/org.bitbucket.tbrugz/sqldump.svg?label=Maven%20Central)](https://search.maven.org/artifact/org.bitbucket.tbrugz/sqldump)
+[![Sonatype Nexus (Snapshots)](https://img.shields.io/nexus/s/org.bitbucket.tbrugz/sqldump?server=https%3A%2F%2Foss.sonatype.org&label=Snapshots)](https://oss.sonatype.org/content/repositories/snapshots/org/bitbucket/tbrugz/)
 [![CI](https://github.com/tbrugz/sqldump/actions/workflows/ant.yml/badge.svg)](https://github.com/tbrugz/sqldump/actions/workflows/ant.yml)