Add light theme

[Nargonath]

This PR is an attempt to fix #24.

To easily toggle between the light/dark background I believe we need to rewrite the colors/spaceduck.vim file and change its structure. For now I only included an example of how I intend to do it. I believe we'll need to remove hi Spaceduck statements in the &background if blocks since they won't be needed anymore once we start using the palette dictionary. I added a custom function to keep the highlight call DRY. I also just changed the hi Normal call to showcase the function use case.

[jinh0]

Hey @Nargonath thanks for making the local highlight function! This was something @pineapplegiant and I have discussed for some time now, though we never got to it. I'm glad you did!

Regarding rewriting the entire colors/spaceduck.vim file with your local highlight function, we need to take this step-by-step.

1. Replace the color variables with the local highlight function.
2. Replace all remaining highlight groups not linked to the color variables
3. Improve the highlight function

One improvement for the highlight function necessary is taking arguments for gui= and cterm= such as

hi SpellBad guifg=#e33400 ctermfg=166 guibg=NONE ctermbg=NONE gui=underline cterm=underline

hi StatusLineTermNC guifg=#000000 ctermfg=0 guibg=#30365F ctermbg=237 gui=reverse cterm=reverse

gui= and cterm= is usually set to NONE but sometimes need different arguments. I think this will be a really quick fix.

I'll test out your code and merge it with the dev branch if there is no further problem.

Thanks!

[Nargonath]

Alright thank you @jinh0 for the feedback. I'll add your suggestion to my MR.

[jinh0]

Hey @Nargonath , sorry for being late. I merged it, adding the gui=NONE option for the highlight function. Everything works 😃 . For now, I changed the way to view the light theme in progress. You'll have to have let g:spaceduck_dev_light_theme = 1 in your vim config to view the light theme. I thought this to be the prudent choice so that nobody accidentally stumbles upon the horror that is the current light theme.

Thanks for the pull request! Looking forward to working more with you!

[Nargonath]

I didn't think you'd want to merge this for now. Good call for the custom variable trigger. I'll open a new PR once I make more progress on the light theme then.