Update readme (#790)

- Fix Java CI badge
- Add Maven Central badge
- Change links to https
- Change wording
- Remove link to plugin as it is no longer correct with the new plugins page

README.md

@@ -1,17 +1,14 @@
 # GORM for Hibernate 5
+[![Maven Central](https://img.shields.io/maven-central/v/org.grails/grails-datastore-gorm-hibernate5.svg?label=Maven%20Central)](https://central.sonatype.com/artifact/org.grails/grails-datastore-gorm-hibernate5) [![Java CI](https://github.com/grails/gorm-hibernate5/workflows/Java%20CI/badge.svg?event=push)](https://github.com/grails/gorm-hibernate5/actions/workflows/gradle.yml)
 
-This project implements [GORM](http://gorm.grails.org/latest/) for the Hibernate 5.
+This project implements [GORM](https://gorm.grails.org/) for the Hibernate 5.
 
 For more information see the following links:
 
-* [Documentation](http://gorm.grails.org/latest/hibernate/manual)
-* [API](http://gorm.grails.org/latest/hibernate/api)
-* [Grails Plugin](https://plugins.grails.org/plugin/grails/hibernate5)
-* ![Java CI](https://github.com/grails/gorm-hibernate5/workflows/Java%20CI/badge.svg)
+* [Documentation](https://gorm.grails.org/latest/hibernate/manual)
+* [API](https://gorm.grails.org/latest/hibernate/api)
 
 For the current development version see the following links:
 
-* [Beta Documentation](http://gorm.grails.org/snapshot/hibernate/manual)
-* [Beta API](http://gorm.grails.org/snapshot/hibernate/api)
-
-
+* [Snapshot Documentation](https://gorm.grails.org/snapshot/hibernate/manual)
+* [Shapshot API](https://gorm.grails.org/snapshot/hibernate/api)