docs: update Maven Central badge to remove version prefixes

Author: DrSatyr

README.md

@@ -5,8 +5,7 @@ Compare two OpenAPI specifications (3.x) and render the difference to HTML plain
 [![Build](https://github.com/OpenAPITools/openapi-diff/workflows/Main%20Build/badge.svg)](https://github.com/OpenAPITools/openapi-diff/actions?query=branch%3Amaster+workflow%3A"Main+Build")
 [![Quality Gate Status](https://sonarcloud.io/api/project_badges/measure?project=OpenAPITools_openapi-diff&metric=alert_status)](https://sonarcloud.io/dashboard?id=OpenAPITools_openapi-diff)
 
-[![Maven Central 2.0.x](https://img.shields.io/maven-central/v/org.openapitools.openapidiff/openapi-diff-core?versionPrefix=2.0)](https://search.maven.org/artifact/org.openapitools.openapidiff/openapi-diff-core)
-[![Maven Central 2.1.x](https://img.shields.io/maven-central/v/org.openapitools.openapidiff/openapi-diff-core?versionPrefix=2.1)](https://search.maven.org/artifact/org.openapitools.openapidiff/openapi-diff-core)
+[![Maven Central](https://img.shields.io/maven-central/v/org.openapitools.openapidiff/openapi-diff-core)](https://search.maven.org/artifact/org.openapitools.openapidiff/openapi-diff-core)
 
 [![Contribute with Gitpod](https://img.shields.io/badge/Contribute%20with-Gitpod-908a85?logo=gitpod)](https://gitpod.io/#https://github.com/OpenAPITools/openapi-diff)
 [![Join the Slack chat room](https://img.shields.io/badge/Slack-Join%20the%20chat%20room-orange)](https://join.slack.com/t/openapi-generator/shared_invite/zt-12jxxd7p2-XUeQM~4pzsU9x~eGLQqX2g)