Add Altair and Altair-X

[ai03-2725]

Description

Adds support for the Altair and Altair-X keyboards.

QMK Pull Request

Altair
Altair-X

VIA Keymap Pull Request

Altair, Altair-X
Apparently the QMK PRs were done so long ago that the Via keymaps were already included in the userspace repo on creation (here and here).

Checklist

• The VIA support for this keyboard is MERGED in QMK master already (MANDATORY)
• VIA keymap is MERGED in VIA userspace master already (MANDATORY)
• The VIA definition follows the guide here: https://caniusevia.com/docs/layouts
• I have a V3 JSON version for this keyboard definition.(MANDATORY)
• I have formatted the JSON file to have consistent formatting with the rest of the repository.
• I have tested this keyboard definition using VIA's "Design" tab.
• I have tested this keyboard definition with firmware on a device.
• I have assigned alpha keys and modifier keys with the correct colors.
• The Vendor ID is not 0xFEED