Tecplot documentation update

See merge request !5

- Google style docstrings use `Args:` and not `Arguments:`
- Stick to markdown *everywhere*.
- The first line in a big docstring `"""` is always a one line summary

Please confirm before I merge :).

Version 2020.4 with bug fixes to retrieve time better from omni and also works with `share/Python/Scripts/prepare_geospace.py`

This reverts commit 0e2d5042.

small bug fix in _urls_omni_hires

See merge request !3

Imf f107

See merge request !2