fix: some hl config not working

[nicholasxjy]

Changes

• Make some hl config works, so we can style some ui

Configuration

require('fff').setup({
    hl = {
      border = "FffBorder", -- FloatBorder from colorscheme
      normal = "FffFloat", -- NormalFloat
      title = "FffTitle", 
      matched = "FffMatched", -- IncSearch

      active_file = "PmenuSel",
    }
})

-- demo custom hl
vim.api.nvim_set_hl(0, "FffBorder", { fg = "#001204", bg = "#001204" })
vim.api.nvim_set_hl(0, "FffFloat", { fg = "#F4EDCC", bg = "#001204" })
vim.api.nvim_set_hl(0, "FffTitle", { fg = "#5b5e5a", bg = "#dbb651", bold = true })
vim.api.nvim_set_hl(0, "FffMatched", { fg = "#F4EDCC", bg = "#EE99C2", bold = true })