Add Lualine support to nord-vim

[lokesh-krishna]

Adds support for Lualine, a Neovim statusline plugin written in Lua. While the theme tries to stay as close as possible to the existing Lightline theme, the filename section uses nord3 as the background rather than nord1 due to that section also determining the color of the background.

Screenshots are attached of the theme in action:

[lokesh-krishna]

Can we move this to the Neovim port once it starts taking shape?

[arcticicestudio]

Hi @lokesh-krishna 👋, thanks for your contribution 👍

A Lua counterpart for lightline/airline is definitely something that will be added to the new port. I'll try to review this PR as soon as possible and maybe merge it until the port is available. Afterwards this project will be "cleaned" anyway like described in nordtheme/nord#157 (comment) and nordtheme/nord#157 (comment).

[arcticicestudio]

I have decided not to include support for Lualine in this repository but only for the upcoming Nord Neovim port. I leave this PR open to use it as reference and allow you (if you want) to reopen it in the new repository later on.

[svengreb]

@lokesh-krishna Thank you (again!) for your patience! 🙏🏼
It‘s been a while since I had free time to focus more on Nord, and my open source projects in general, and invest time in this issue due to work-life balance.

I recently published the first “Northern Post — The state and roadmap of Nord“ announcement which includes all details about the plans and future of the Nord project, including the goal of catching up with the backlog. This issue is part of the backlog and therefore I want to triage and process it to get one step closer to a “clean state“. Read the announcement about reaching the “clean“ contribution triage state in Nord‘s discussions for more details about the goal.

Therefore it has been added to the icebox in the central and single-source-of-truth project board that is also described in more detail in the roadmap announcement.

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@lokesh-krishna Thanks (again!) for your contribution 🚀
The pull request has been added to the icebox and will be adapted to the new and upcoming Neovim port.