Feature #2821 prepare v6.0.0 release (#2843)

* update release version

* update release date

* compile release notes and update development timeline

* update existing builds DockerHub info

* rotate author list but put Tara first in memoriam

* bold some release notes

* add additional release notes for bugfixes and documentation updates since rc1 release

* update dates to reflect actual release date

* added Michelle to author list

* requested changes from @JohnHalleyGotway PR review

docs/Users_Guide/existing_builds.rst

@@ -536,29 +536,29 @@ in the
 .. dropdown:: DockerHub
 
    | **MET**
-   | *Last Updated: November 14, 2024*
+   | *Last Updated: December 19, 2024*
 
       .. code-block:: ini
 
-          docker pull dtcenter/met:12.0.0-rc1
+          docker pull dtcenter/met:12.0.0
 
      `dtcenter/met DockerHub <https://hub.docker.com/r/dtcenter/met>`_
 
    | **METplus**
-   | *Last Updated: November 14, 2024*
+   | *Last Updated: December 19, 2024*
 
       .. code-block:: ini
 
-          docker pull dtcenter/metplus:6.0.0-rc1
+          docker pull dtcenter/metplus:6.0.0
 
      `dtcenter/metplus DockerHub <https://hub.docker.com/r/dtcenter/metplus>`_
 
    | **METplus Analysis**
-   | *Last Updated: November 14, 2024*
+   | *Last Updated: December 19, 2024*
 
       .. code-block:: ini
 
-          docker pull dtcenter/metplus-analysis:6.0.0-rc1
+          docker pull dtcenter/metplus-analysis:6.0.0
 
      `dtcenter/metplus-analysis DockerHub <https://hub.docker.com/r/dtcenter/metplus-analysis>`_