Update Jetstream2 Matthew tutorial for MS-CC workshop (#71)

* Update the instructions for smoother workflow and more accuracy

Changes in this batch:
* Add information about getting ACCESS allocations.
* Put SSH key info into a dropdown as it is no longer required.
* Update the instance requirements section.

More changes are coming.

* Finish updating the tutorial

Changes here include:
* Pivoting the logging in section to using Web Desktop.
* Moving the Managing an Instance section to the end.
* Removing the Docker installation section.
* Adding a visualization section after METplus runs.
* Other odds and ends.

* Address RST errors in the submission

* Trying again to fix the dropdowns

* Switch incorrect Markdown dropdowns to RST

* Another try to fix the dropdowns

* Update conf.py for sphinx design