Feat: Adds sleep/shutdown LED

[ahoneybun]

Description

• Adds RGBLIGHT_SLEEP to the config.h file for the launch_1.
• Fixes typo in building instructions.

Types of Changes

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

Issues Fixed or Closed by This PR

• LEDs do not turn off with the system and has to be disconnected from the system instead.

[XV-02]

Proposed fix didn't address the issue. Seems an upstream solution is present, but will required separate, future investigation.