fix: attach plugin args to the entry method for better future optimization possibilities

[sxyazi]

Fixes #587

As no new version has been released yet, this is not considered a breaking change.

Now please use:

return {
  entry = function(self, args)
    ya.err(args[1]) -- "foo"
    ya.err(args[2]) -- "bar"
  end,
}

to access the arguments of the plugin.