Add org “ErgoGain” and request PID 0x2358 for “ErgoGain”

[Won-CCS]

This PR adds my organization page and requests a new PID under VID 0x1209.

• Organization: ErgoGain

  • Path: org/ErgoGain/index.md
  • Site: https://github.com/Won-CCS

• Device: ErgoGain (split ergonomic keyboard)

  • Path: 1209/2358/index.md
  • Firmware: QMK-based with a custom PMW3610 pointing-device driver
  • Source (buildable): https://github.com/Won-CCS/ErgoGain
    • The repository includes a QMK firmware submodule pinned to a fixed commit for reproducible builds.
  • License: MIT for hardware/docs; firmware follows QMK’s GPL licensing

Checklist

• org/ErgoGain/index.md added with basic org info
• 1209/2358/index.md added with layout: pid, owner: ErgoGain, and source: pointing to buildable sources (PCB + firmware)
• PID 0x2358 is unclaimed (selected as available)
• Repository includes instructions to reproduce the firmware build (submodule + commands)

Thank you for reviewing the request!