Add support for LAYOUT_alice to sneakbox pcb

[stanrc85]

Update sneakbox/aliceclone to support LAYOUT_alice default layout.

Description

I have tested that the keymaps compile without error:
-km default
-km via
-km default_alice
-km stanrc85-alice

There are no other user layouts for the pcb that would be affected.

Types of Changes

• Core
• Bugfix
• New feature
• Enhancement/optimization
• Keyboard (addition or update)
• Keymap/layout/userspace (addition or update)
• Documentation

Issues Fixed or Closed by This PR

Checklist

• My code follows the code style of this project: C, Python
• I have read the PR Checklist document and have made the appropriate changes.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• I have tested the changes and verified that they work and don't break anything (as well as I can manage).