Add Ubuntu Terminal theme

[RicHincapie]

Pull Request Template

Discord username (optional)

NA

Name of theme

Ubuntu

How Has This Been Tested?

Have you run the python script? python3 ./scripts/gen_theme_previews.py <folder-name-eg-standard> - Yes Tried in my local Warp

Notes

We cannot accept pull request that include custom background images because:

• of licensing restrictions
• we are trying to keep the binary size of the repo as small as possible (just the yaml files)

If your theme has an intended custom background image, include a comment in the yaml with a link to where people should download it.

[RicHincapie]

@elviskahoro wdyt?

[DaveParr]

I realise you likley were asking a maintaner, but FWIW I love it 👍🏻