Revamp dactyl_manuform directory

[dunk2k]

Restructure dactyl_manuform directory in line with #21492

Description

• moved *_5 variants to dactyl_manuform_mini directory
• moved 3 thumb key cluster variants to dactyl_manuform_tight directory
• added aliases for variants that have been moved/renamed
• added readme.md per variant
• layout aliases added, per variant, for prior layout macro name
• where none existed prior:
  • added via keymap per variant
  • added license headers to .c and .h files
• removed config.h files with MASTER LEFT defined only
• removed rgblight definitions as dactyl manuform does not have a standard/convention for them
  • keymaps that used prior rgblight definitions have them added to their respective directory

cc: @l4u - regarding dactyl_manuform_mini/ directory

Types of Changes

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

Issues Fixed or Closed by This PR

• n/a

Checklist

• [x] My code follows the code style of this project: C, Python
• [x] I have read the PR Checklist document and have made the appropriate changes.
• [ ] My change requires a change to the documentation.
• [x] 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).