[Keymap] Reorganization, cleanup and readmes for drashna code

[drashna]

Description

• Add readmes for userspace features that didn't have them.
• Separate out userspace code into more logical units
• Add folders for userspace, to keep folder cleaner
• Pull out pointing device user code into userspace
• Force disable optimization for autocorrect
• Add watchdog reset for split syncing
• Add Keyboard reboot code (eg, reset but not into bootloader)
• Add file for all per user tap-hold functions
• Cleanup oled font file a bit
• Replace userspace copyright headers with spdx version
• Fix up userspace rules
• Fix up various keyboards not compiling properly

Types of Changes

• Enhancement/optimization
• Keymap/layout/userspace (addition or update)
• Documentation

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).