Color Highlighting documentation

Start with the README's Highlight and Example Config sections, then review issues 489, 473, and 226 for the existing context. Document where the listed highlight groups should be defined in the provided Lua configuration, and update the example so the placement and usage are clear.

This isn't well documented, I've already viewed multiple issues regarding this with the responses being not so helpful, to not helpful at all.

Documentation states there are highlight groups available for configuration
But where should this be defined in a configuration? An updated example in this section would be helpful, but as I've seen so far, each individual asking about this has had their issue answered and then immediately closed - none of these answers have been helpful thus far.

First issue searched, Again, where does DashboardDesc reside?
Second issue, I shouldn't need to change themes.
Third issue, yeah, the highlight groups are in the readme, but where should those reside in the configuration, should it be an autocommand, or a property in the lua file where this is loaded?

The highlight groups documented have zero context around them and does not speak to where they should exist.

Some information here, or an updated example would be helpful. Maybe I'm just being a moron, but I'll gladly admit to it and update the example if concrete advice is given.

return {
    'nvimdev/dashboard-nvim',
    event = 'VimEnter',
    config = function()
        require('dashboard').setup {
            theme = 'doom',
            config = {
                header = {
                    -- Some ASCII image
                },
                center = {
                    {
                        icon = ' ',
                        icon_hl = 'Group',
                        desc = 'Configure NeoVim [C]onfiguration files',
                        desc_hl = 'String',
                        key = 'c',
                        keymap = '<leader>sn',
                        key_hl = 'Number',
                        key_format = ' [%s]',
                        action = 'Telescope find_files',
                    },
                },
                footer = {
                    -- Some ASCII image
                },
                vertical_center = true,
            },
        }
    end,
    dependencies = { 'nvim-tree/nvim-web-devicons' },
}