Allow globs to apply to '..' and '.'

[Jackenmen]

Fixes #847

---

TODO

• Use cargo fmt
• Add necessary tests
• Add changelog entry
• Update default config/theme in README (if applicable)
• Update man page at lsd/doc/lsd.md (if applicable)

[muniu-bot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: Jackenmen

The full list of commands accepted by this bot can be found here.

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[Jackenmen]

I manually tested this and it acts about as I would expect it to - . on the ignore-globs only hides ., .. only hides .., and having both on the list hides both.

Let me know if I should add any unit tests for this. I looked at the existing tests in the file I edited and there didn't seem to be any testing anything to do with ignore_globs so I figured it might not be necessary.