https://neovim.io/doc/user/lua.html
https://neovim.io/doc/user/lua-guide.html
:lua print("hello")

https://neovim.io/doc/user/lua-guide.html#lua-guide-variables
:lua vim.print(vim.g.clipboard)
:lua print(vim.g.clipboard)

https://github.com/nanotee/nvim-lua-guide/blob/master/README.md#using-meta-accessors-1
    vim.g
    vim.b
    vim.w
    ...