Staging repository URL changed (#511)

Signed-off-by: David Kral <david.k.kral@oracle.com>

README.md

@@ -1,7 +1,7 @@
 # Eclipse Yasson
 
 [![Maven Central](https://img.shields.io/maven-central/v/org.eclipse/yasson.svg?label=Maven%20Central)](https://mvnrepository.com/artifact/org.eclipse/yasson)
-[![Sonatype Nexus (Snapshots)](https://img.shields.io/nexus/s/https/oss.sonatype.org/org.eclipse/yasson.svg)](https://oss.sonatype.org/content/repositories/snapshots/org/eclipse/yasson/)
+[![Jakarta Staging (Snapshots)](https://img.shields.io/nexus/s/https/jakarta.oss.sonatype.org/org.eclipse/yasson.svg)](https://jakarta.oss.sonatype.org/content/repositories/staging/org/eclipse/yasson/)
 [![Gitter](https://badges.gitter.im/eclipse/yasson.svg)](https://gitter.im/eclipse/yasson)
 [![Javadocs](https://www.javadoc.io/badge/org.eclipse/yasson.svg)](https://www.javadoc.io/doc/org.eclipse/yasson)
 [![Build Status](https://github.com/eclipse-ee4j/yasson/actions/workflows/maven.yml/badge.svg?branch=master)](https://github.com/eclipse-ee4j/yasson/actions/workflows/maven.yml?branch=master)