Issue/#482 improve documentation

[Askaholic]

Not quite done with this.

• Rewrite param docs to use markdown instead of rst
• Add doctests to pytest
• Remove server.abc

#482

[codecov]

Codecov Report

Merging #753 (e67e2e4) into develop (e174f77) will increase coverage by 0.05%.
The diff coverage is 96.66%.

Impacted Files	Coverage Δ
server/asyncio_extensions.py	100.00% <ø> (ø)
server/config.py	100.00% <ø> (ø)
server/configuration_service.py	100.00% <ø> (ø)
server/control.py	86.48% <ø> (ø)
server/core/__init__.py	100.00% <ø> (ø)
server/core/dependency_injector.py	100.00% <ø> (ø)
server/db/__init__.py	74.19% <ø> (ø)
server/factions.py	94.73% <ø> (ø)
server/game_service.py	99.01% <ø> (ø)
server/games/__init__.py	100.00% <ø> (ø)
... and 36 more

[Askaholic]

Merging this because it makes some progress, but I don't see myself working on it further in the near future.