mention the File deploy in the guides

Fixes #341

lib/Statocles/Help/Deploy.pod

@@ -129,6 +129,32 @@ And give it to our site:
 Now when we run C<statocles deploy>, our repository will be updated and so will
 our web root C</var/www/www.example.com>.
 
+=head1 File
+
+If you only need to copy the files to another directory to serve them, if
+you're writing the site on the web server, or you've got a Jenkins server that
+can build the site, you can use the L<File deploy|Statocles::Deploy::File>.
+This deploy simply copies the built website to another directory.
+
+    # site.yml
+    file_deploy:
+        class: Statocles::Deploy::File
+        args:
+            path: /var/www/www.example.com
+
+    site:
+        class: Statocles::Site
+        args:
+            deploy: { $ref: file_deploy }
+
+This is the default deploy. If you just give a path to the site object, the
+site will be copied to that path:
+
+    site:
+        class: Statocles::Site
+        args:
+            deploy: /var/www/www.example.com
+
 =begin comment
 
 # XXX: Make Statocles::Deploy::Command for this!