Co-authored-by: Martin Schroschk <martin.schroschk@tu-dresden.de>

- Remove ssd filesystem

- Initially, I just wanted to replace taurusexport command
- It ended up with a review of the Mathematica stuff

- Start filling the Power9 page
- Change links within documentation to point to hardware overview
  section

- Architecture and hardware is well documented on hardware overview page
- Documentation of Slurm, Workspaces and Filesystems are not special to
  Barnard; thus, users should read the corresponding pages
- Currently, we do not have a special topic that needs to covered on a
  separate Barnard page
- Reduce complexity of documentation
- Fix links; Link to subsection "Barnard" in hardware overview page

All `Python` modules now export `PIP_REQUIRE_VIRTUALENV=true`.
This causes an error when users try to use `pip install` without an
active virtualenv.
This also avoids admins accidentally installing/changing Python packages
in the global module.

update pika page: add 2 metrics; add download jobdata screenshot, explanation and example; remove haswell warning

Update python_virtual_environments.md: insert missing line. When executing this example, there is a conda init error raised if this line was not executed previously.

- Currently no such partition available on any cluster

- Fix some line breaking
- Fix some long slurm options