Fix: wrong group name

[kunzaatko]

Typo in group names:
PMenuSel -> PmenuSel
PMenu -> Pmenu

[arcticicestudio]

Hi @kunzaatko 👋, thanks for your contribution 👍
Also thanks for your patience, the large amount of tasks for the Nord project are really time consuming and free time is kind of rare.

Looks good to me 👍🏻
I guess this mismatch was never really noticed because most of the time users rely on plugins like coc or vim-clap which come with custom highlighting groups and UI libraries.

[kunzaatko]

I actually would not notice it either, if it were not for the neovim fork I was making. I have already written an e-mail to you about it, but I guess it must have disappeared in the flood of e-mails you are getting. Here it is nord.nvim. In the e-mail, I was asking whether you would maybe want to adopt it as a neovim fork, since the colour groups of neovim against vim are slowly diverging. It is an exact copy apart from it including the additional groups.

[arcticicestudio]

Sorry for not replying, I've moved your email into the "queue" directory, but the time to process all of them is rare 😐
I know there is currently some movement regarding the Neovim v0.5 release and its long-awaited features like TreeSitter. There are contributions like arcticicestudio/nord#157 and yours, but I need to understand what are the differences and the actual advantages between a "normal" Vim color scheme plugin and a one that is scoped to Neovim. When there are no real advantages but only satisfying the "because its new and Lua", creating an additional Neovim theme to the official Nord ports will add almost 98+% maintenance overhead.

Anyway, I'll try to find some time this weekend to post a reply in all the issues & PRs regarding this topic and also finally implement support for TreeSitter.