This adds two more tables to the run reference documentation.
- the list of 'modes' for Network settings is now a table.
- the "note" for `--net="host"` was moved from the list to the detailed
description.
- the 'options' for "Runtime constraints on CPU and memory" are
now a table
- slightly re-worded the description for "memory" options, e.g.
"It is not allowed..." was rewriten to "The *container* is not allowed..."
- fix example in "Runtime privilege, Linux capabilities, and LXC configuration"
being indented twice
- slightly reduced indenting in some `usage` output to be better readable.
- fixes a typo `/ets/hosts` -> `/etc/hosts`
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>