Service Provider in readme is incorrect

[adamcmoore]

Small issue - in the readme it states that the service provider is

FactoryStories\Providers\StoryFactoryServiceProvider::class,

Whereas it should be

FactoryStories\Providers\ServiceProvider::class,

Also it should be stated that the stories directory should be added to the autoload classmap:

"autoload": {
    "classmap": [
        "database/seeds",
        "database/factories",
        "database/stories",
    ],
}