Iron180 LED backlight fix

[Gondolindrim]

Provides LED backlight capability to the Iron180 PCB.

Some quality-of-life improvements were also made, mainly to code comments and the README. They are:

• Adding new information to the readme, like a picture of the keyboard, a small guide on how to DFU and flash the PCB and updating the information on the groupbuy status;
• Removing the auto-generated qmk chibios-confmigrate messages on the files;
• Fixed the "2015" year on some files;
• Remove uneeded comments on config.h.
• Added a RESET key to the default firmware.

Types of Changes

• Core
• Bugfix
• New feature
• Enhancement/optimization
• Keyboard (addition or update)
• 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).