feature: snacks.picker support

[theol0403]

New picker is awesome: https://github.com/folke/snacks.nvim/blob/main/docs/picker.md

But, it is broken with this theme:

Fzf, by contrast, is beautiful.

If no one wants to tackle this, I'll take a look one day when I have a chance and make a PR.

[narutozxp]

override  = function(c) 
    return {
    ["NonText"] = {fg = "#545c7e"},
}
end,

[theol0403]

Needs to be more than that, primarily in the background and border lines. That nontext color also does not seem like a real theme color

[theol0403]

Found some time to tackle this. As far as I can tell, this is all that is needed:

override = function(c)
  local hp = require("monokai-pro.color_helper")
  local common_fg = hp.lighten(c.sideBar.foreground, 30)
  return {
    SnacksPicker = { bg = c.editor.background, fg = common_fg },
    SnacksPickerBorder = { bg = c.editor.background, fg = c.tab.unfocusedActiveBorder },
    SnacksPickerTree = { fg = c.editorLineNumber.foreground },
    NonText = { fg = c.base.dimmed3 }, -- not sure if this should be broken into all hl groups importing NonText
  }
end,
})

Edit: made some more tweaks

[bfouts]

this may help someone..
SnacksPickerDirectory = { fg = c.editorLineNumber.foreground }