Plugins
vdoc can be extended with plugins. All plugins are inactive by default and need to be configured before they do anything.
Each plugin reads its own section of the configuration file,
under plugins.<name>. Every setting can equally be given as an environment variable, named
VDOC_PLUGINS_<NAME>_<SETTING>, which then takes precedence over the file.
A setting that holds a structure of its own is addressed with __ between the levels, for example
VDOC_PLUGINS_THEME_LIGHT__LOGO_URL for what the file writes as plugins.theme.light.logo_url.
Theme plugin
vdoc can be extended with a theme plugin, which carries the logo and the colors the frontend uses.
Site plugin
vdoc can be extended with a site plugin, which says what a given instance of vdoc is. vdoc itself
Footer plugin
vdoc can be extended with a footer plugin, which renders a copyright line and groups of links
Orama plugin
vdoc can be extended with an Orama plugin, which puts a search box in the header that searches