Added directory directive to Overview.

[nobodyspecial1553]

Fixes #251

[laytan]

The order is a bit random, might make the most sense to go directory -> file -> procedure -> line, but it's fine anyway 👍

[nobodyspecial1553]

That's fair. I suppose my logic was that it should be next to #file, so I just appended it to #file without thinking all that deeply about it.

Putting #procedure before #line is sensible to me, but it was originally #line then #procedure, so I didn't even consider changing the order of that.