Add support for mini_mighty/kbd.

[dimitrix-llc]

Description

Add support for the "mini-mighty-kbd" - a 74-key, low profile, small form factor, wired mechanical keyboard with hot-swappable switches, featuring a fully 3D printable enclosure and keycaps with an open source design, offering endless possibilities for customization and creativity. Made by dimitrix-llc.

Added the necessary readme, config and keymap files under keyboards/mini_mighty/kbd.
The "mini_mighty" is added as a folder with "kbd" as a sub-folder, since we have a couple more project in development, that we're planning to add to the "mini_mighty" folder in the near future.

Types of Changes

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

Issues Fixed or Closed by This PR

• N/A

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).