feat(#560): scandir adds link entry if it is a directory.

[SalOrak]

Hi, I'm the author of Whaler.nvim. I had a feature added ( issue here ) to the plugin which under the hook uses plenary.

The idea is that whaler scan for subdirectories in a directory specified by the user but in the current state of plenary.nvim it does not contemplate symlinks to directories.

This PR modifies the scandir function (sync only) adding symlinks directories when found. It does not apply any recursion whatsoever.

Following issue #560