docs: make custom root info removable

docs: make custom root info removable

By default Girocco generates it's own root certificate and
uses that to sign a web server certificate which can then
be used to serve https traffic.

It's relatively simple to use a non-Girocco-generated
web server certificate, but the documentation continues
to provide instructions on how to configure and trust
the Girocco-generated root (which may be counter
productive in such a case).

Introduce a new config option Girocco::Config::pretrustedroot
that when set to a true value suppresses this extra
documentation from appearing on the web site and also
suppresses the availability of the Girocco-generated root
certificate (since it's likely irrelevant and possibly
conterproductive in that case).

And while in there fix a few minor typos that have somehow
survived to this point undetected.

Signed-off-by: Kyle J. McKay <mackyle@gmail.com>