docs: Add new shields.io badge for coqorg/coq:latest

* This patch subsumes PR #15001

README.md

@@ -36,6 +36,7 @@ environment for semi-interactive development of machine-checked proofs.
 [![nixpkgs unstable package][nixpkgs-badge]][nixpkgs-link]
 
 [![Docker Hub package][dockerhub-badge]][dockerhub-link]
+[![latest dockerized version][coqorg-badge]][coqorg-link]
 
 [repology-badge]: https://repology.org/badge/latest-versions/coq.svg
 [repology-link]: https://repology.org/metapackage/coq/versions
@@ -61,6 +62,9 @@ environment for semi-interactive development of machine-checked proofs.
 [dockerhub-badge]: https://img.shields.io/badge/images%20on-Docker%20Hub-blue.svg
 [dockerhub-link]: https://hub.docker.com/r/coqorg/coq#supported-tags "Supported tags on Docker Hub"
 
+[coqorg-badge]: https://img.shields.io/docker/v/coqorg/coq/latest
+[coqorg-link]: https://github.com/coq-community/docker-coq/wiki#docker-coq-images "coqorg/coq:latest"
+
 Please see https://coq.inria.fr/download.
 Information on how to build and install from sources can be found in
 [`INSTALL.md`](INSTALL.md).