fix(rss): Don't error if the RSS folder doesn't exist.
fix(rss): Don't error if the RSS folder doesn't exist.

It just happened to work if
- You had posts (more than likely)
- Your RSS file was in the root directory of your site

Otherwise, the destination directory wouldn't exist and you would get an
error.

cobalt-org/cobalt.rs,cobalt-org/cobalt.rs,cobalt-org/cobalt.rs,cobalt-org/cobalt.rs