[[!template id=plugin name=underlay author="[[Simon_McVittie|smcv]]"]]
[[!tag type/special-purpose]]

This plugin adds an `add_underlays` option to the setup file. Its value is
a list of underlay directories whose content is added to the wiki.

Multiple underlays are normally set up automatically by other plugins (for
instance, the images used by the [[plugins/smiley]] plugin), but they can
also be used as a way to pull in external files that you don't want in
revision control, like photos or software releases.

Directories in `add_underlays` should usually be absolute. If relative,
they're interpreted as relative to the parent directory of the basewiki
underlay, which is probably not particularly useful in this context.