feature: bail-out when user does not supply any options

[abeldekat]

Currently, without options, the plugin activates and enables only lazy.nvim, LazyVim and tokyonight.
This is not convenient.

Expected:

  { -- 1
    "abeldekat/lazyflex.nvim",
    import = "lazyflex.plugins.intercept",
    opts = {}
  },

The plugin should return early, doing nothing. The same behavior is expected when the opts keyword is not specified.