manly dpkg -S

manly doesn't seem to find -S because it's in a more indented section of the `dpkg` manual page than most other options

```
$ manly dpkg -S
manly: No matching flags found.
$ man dpkg | grep '  -S'
              -S, --search filename-search-pattern...
$ man dpkg | grep '  -r'
       -r, --remove package...|-a|--pending
```