this is server side, and a more standard format, and thus I like it more
than mermaid, which I've been using at work. but, I really wanted a
server-side option (see my manifesto) for drawing relationship graphs,
for D&D stuff of all things.
this adds an optional 'graphviz' feature to package installation which
consequently depends on pydot
this tweaks the behavior of the title to always append ' - suffix' to
any title (from the meta tag, or generated via request path), unless the
page explicitly specifies an empty Title meta tag
this code was getting too messy and scattered, and I realized that Flask
wasn't doing as much as I thought it was here, so now we need more
safety and sanity checks
this has a really basic template and whatnot at the moment, so
styling/etc isn't done, but this is maybe the last major piece before I
could actually see pushing this onto the site
