Horizon Bright Theme per Bullfinch

Based on the Horizon Bright theme for VS Code:
https://horizontheme.netlify.app/

More Horizon themes:
https://addons.mozilla.org/en-US/firefox/addon/horizon-dark-theme/

More light themes:
https://addons.mozilla.org/en-US/firefox/addon/rose-pine-dawn-light-theme/
https://addons.mozilla.org/en-US/firefox/addon/solarized-light-theme/
https://addons.mozilla.org/en-US/firefox/addon/gruvbox-light-theme/
https://addons.mozilla.org/en-US/firefox/addon/everforest-light-soft-theme/
https://addons.mozilla.org/en-US/firefox/addon/kanagawa-lotus-light-theme/
https://addons.mozilla.org/en-US/firefox/addon/nord-light-theme/
https://addons.mozilla.org/en-US/firefox/addon/sunny-peach-light-theme/