Add Nord Semi-Light preset

[salarua]

New Preset: Nord Semi-Light

As this is a variant of an existing preset, I'm leaving it on draft status until there's a system in place for distinguishing different versions apart.

Description

An arctic, north-bluish color palette.

Palette

Nord

Screenshots (optional)

Wallpaper

Checklist

Before submitting the PR, I checked:

• [x] I've only modified one preset
• [ ] I've added the URL to my raw preset in presets.json
• [x] I've checked the format of each json files I modified
• [ ] (optional) I've added screenshots
• [x] The preset name is following preset naming guidelines.

Publication

• [x] I want to add my preset in the preset list.

Thanks for your submission we will review and merge it as quick as possible.

[salarua]

This is currently waiting on the existing Nord preset to make it into Official.