Update Junit5 Extension Page to newer version

Just released the version 1.0.0, which is compatible with 3.0.0-M7 and has some more features.

https://github.com/fabriciorby/maven-surefire-junit5-tree-reporter

So it would be good to have an update on the website, in order to do this I can contributing by creating the PR, but I don't know how to preview the text with this .vm extension to check if everything is all right.

https://github.com/apache/maven-surefire/blob/master/maven-surefire-plugin/src/site/apt/examples/junit-platform.apt.vm