moving this allows for per-instance customizations later, but that won't
be practical until serving styles from the instance dir is also allowed.
but, this sets the ground work and does allow for removing some styles
(e.g. if someone wanted to only allow 'plain').
also I still need to add the ability to present the themes list dynamically
without this, the code fence parser was getting thrown off if you didn't
have the pydot extension loaded, which was thwarting backwards
compatibility. this makes the pydot bits look like an attribute to the
vanilla parser, so at least then the vanilla markdown renders as
intended
I didn't like the other figure + figcaption parsers, they either assumed
a lot about usage (e.g. images only), or they were inline parsers that
either wrapped the figure in a paragraph tag (which is incorrect syntax)
or did span trickery (annoying)
so, this handles images and maybe other things, and does things properly
with figures as their own blocks. incomplete but it works with my
images, and should allow for looping (for multi-line content) in the
future?
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
* works on a path now, not a file location
* as such is sliiiiiightly easier to understand
* now also puts the current page in the nav
* fixed failing test where this caused an error (rather than 404) on
non-existent paths
