Add lazy.vim instructions to the README

[yonas]

Add lazy.vim instructions to the README:

return {
    "wfxr/minimap.vim",
    build = "cargo install --locked code-minimap",
    lazy = false,
    cmd = { "Minimap", "MinimapClose", "MinimapToggle", "MinimapRefresh", "MinimapUpdateHighlight" },
    init = function()
        vim.cmd("let g:minimap_width = 10")
        vim.cmd("let g:minimap_auto_start = 1")
        vim.cmd("let g:minimap_auto_start_win_enter = 1")
    end,
}

-- @CnsMaple https://github.com/wfxr/minimap.vim/issues/179#issuecomment-1600367171

FreeBSD users can install minimap via ports: pkg install code-minimap and comment out build = "cargo install --locked code-minimap",