Installation instruction for lazy package manager

[aap01]

No description provided.

[Rocco-Gossmann]

You may also need to add ft = {"markdown"}.
Else Lazy.nvim may not load the plugin, when opening a Markdown file.
(At least on NvChad)

{ "iamcco/markdown-preview.nvim",
	ft={"markdown"},
	build = function() vim.fn["mkdp#util#install"]() end,
},

[aap01]

Actually, I tested the config in Lunarvim and it works fine there.
I can test the config with ft parameter in Lunarvim's lazy plugin manager.
And, if it works, I will update the MR.