doc: proofread of the all reST sources (no content change)

Normalize reST sources with best practice and KISS in mind.

to name a few points:

- simplify reST tables
- make use of ``literal`` markup for monospace rendering
- fix code-blocks for better rendering in HTML
- normalize section header markup
- limit all lines to a maximum of 79 characters
- add option -H to the sudo command used in code blocks
- drop useless indentation of lists
- ...

[1] https://www.sphinx-doc.org/en/master/usage/restructuredtext/basics.html



Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>