Handle multiple directories.

Create a way to handle multiple directories so that a site can have:

site-root
|
+-> Blog
|   |
|   +-> 2019
|   +-> 2020
+-> Content
    |
    +-> About
    +-> Contact

Or something like that. And be able to do that with a single command.

As things currently stand, it could actually be reasonably handled, as it's not likely that sitewide updates are that common (at this point).

Though a change to the header and footer files might mean needing to update large portions of a site all at once to get it to update correctly.

Also, some content would be handled with something like a rsync command as trying to parse it like markdown would cause problems.