update README to link the 3.10.0 release to the Dockerfile it was built from in git (#1101)

Author: kkloberdanz

extras/docker/README.md

@@ -16,6 +16,7 @@ is also known as
 
 ## Tags
 
+- [3.10.0-redhat-ubi-9.3](https://github.com/mongodb/mongo-cxx-driver/blob/7fa047f64b476b7b7c422afc9b92eafde41f3412/extras/docker/redhat-ubi-9.3/Dockerfile)
 - [3.9.0-redhat-ubi-9.3](https://github.com/mongodb/mongo-cxx-driver/blob/fe02b0dbb930d0fb28ca704bc5cfc0b31160d860/extras/docker/redhat-ubi-9.3/Dockerfile)
 - [3.8.1-redhat-ubi-9.2](https://github.com/mongodb/mongo-cxx-driver/blob/5b1b515e1b355943003d72a04ae47a9e0e174374/extras/docker/redhat-ubi-9.2/Dockerfile)
 - [3.8.0-redhat-ubi-9.2](https://github.com/mongodb/mongo-cxx-driver/blob/cb9dc3e927299bb9d2f2dc04878234e32c129685/extras/docker/redhat-ubi-9.2/Dockerfile)