Add iamcco/markdown-preview.nvim

[apicgg]

Checklist:

• The plugin is specifically built for Neovim, or if it's a colorscheme, it supports treesitter syntax.
• The lines end with a .. This is to conform to awesome-list linting and requirements.
• It's not already on the list.
• The title of the pull request is Add/Update/Remove `username/repo` when adding a new plugin.
• The description doesn't start with A Neovim plugin for.., or A plugin for...
• The description doesn't mention that it's a Neovim plugin, it's obvious from the rest of the document.
• Neovim is spelled as Neovim (not nvim, NeoVim or neovim), Vim is spelled as Vim (capitalized), Lua is spelled as Lua (capitalized).

[thetic]

• Add markdown preview plugin #100
• Add iamcco/markdown-preview.nvim #571
• Remove iamcco/markdown-preview.nvim #573

[apicgg]

I have just checked the issue #574 related to this. I am closing this PR as there is no plan to include these types of plugins for now. Will that be okay @tversteeg ?

[ofirgall]

@apicgg I support vim plugins that doesn't has Lua alternative, since my PR a Lua markdown preview has been released, https://github.com/toppair/peek.nvim.

[tversteeg]

@apicgg Yes that's okay, thanks for the PR anyway!