[bugfix] Tidy up badges, add Docker Images, and fix Slack invite link

Author: adamretter

README.md

@@ -13,8 +13,9 @@
 [![Java 8](https://img.shields.io/badge/java-8-blue.svg)](https://adoptopenjdk.net/)
 [![License](https://img.shields.io/badge/license-LGPL%202.1-blue.svg)](https://www.gnu.org/licenses/lgpl-2.1.html)
 [![Download](https://img.shields.io/github/v/release/evolvedbinary/elemental.svg)](https://github.com/evolvedbinary/elemental/releases/)
-[![Maven Central](https://maven-badges.herokuapp.com/maven-central/xyz.elemental/elemental/badge.svg)](https://search.maven.org/search?q=g:xyz.elemental)
-[![Slack](https://img.shields.io/badge/elemental-slack-3e103f.svg)](https://join.slack.com/t/elemental-xyz/shared_invite/zt-3290ginoh-lWocaoR3UMw7jghfrt~kFA)
+[![Maven Central](https://img.shields.io/maven-central/v/xyz.elemental/elemental?logo=apachemaven&label=maven+central&color=green)](https://search.maven.org/search?q=g:xyz.elemental)
+[![Docker Image Version](https://img.shields.io/docker/v/evolvedbinary/elemental?sort=semver&logo=docker&logoColor=white&label=docker)](https://hub.docker.com/r/evolvedbinary/elemental)
+[![Slack](https://img.shields.io/badge/elemental-slack-3e103f.svg)](https://join.slack.com/t/elemental-xyz/shared_invite/zt-34r53san4-fzHCV0vDT9lYSMChUdn3cQ)
 [![Code of Conduct](https://img.shields.io/badge/code%20of%20conduct-contributor%20covenant-%235e0d73.svg)](https://www.contributor-covenant.org/version/2/1/code_of_conduct.html)
 
 ---
@@ -34,14 +35,15 @@ The best place to seek help or support is in our public [Slack](https://join.sla
 
 -   **Homepage:** [https://www.elemental.xyz](https://www.elemental.xyz)
 -   **Binaries:** [https://www.elemental.xyz/downloads](https://www.elemental.xyz/downloads)
+-   **Docker Images:** [https://hub.docker.com/r/evolvedbinary/elemental](https://hub.docker.com/r/evolvedbinary/elemental)
 -   **Documentation:** [https://www.elemental.xyz/documentation](https://www.elemental.xyz/documentation)
 -   **Book:** [https://www.oreilly.com/library/view/exist/9781449337094/](https://www.oreilly.com/library/view/exist/9781449337094/)
 -   **Packages:** [https://exist-db.org/exist/apps/public-repo](https://exist-db.org/exist/apps/public-repo)
 -   **Source code:** [https://github.com/evolvedbinary/elemental](https://github.com/evolvedbinary/elemental)
 -   **Git clone URL:** `git://github.com/evolvedbinary/elemental.git`
 -   **Mailing list:** [https://groups.google.com/u/1/a/elemental.xyz/g/users](https://groups.google.com/u/1/a/elemental.xyz/g/users)
 -   **LinkedIn:** [https://www.linkedin.com/groups/10070373/](https://www.linkedin.com/groups/10070373/)
--   **Slack:** [https://elemental-xyz.slack.com](https://join.slack.com/t/elemental-xyz/shared_invite/zt-3290ginoh-lWocaoR3UMw7jghfrt~kFA)
+-   **Slack:** [https://elemental-xyz.slack.com](https://join.slack.com/t/elemental-xyz/shared_invite/zt-34r53san4-fzHCV0vDT9lYSMChUdn3cQ)