Minor improvement in documentation

[ebergsma]

First of all, thank you for this awesome package.

I ran into this when I a collegue wanted to change the default behaviour of a model's returned url (create a different priority).
In your example, you show how to add the functionality to the model, only returning a string of its route.
This is the current example:

use Spatie\Sitemap\Contracts\Sitemapable;
use Spatie\Sitemap\Tags\Url;

class Post extends Model implements Sitemapable
{
public function toSitemapTag(): Url | string | array
{
return route('blog.post.show', $this);
}
}

It does clearly show the returnable types, but perhaps an example like:

use Spatie\Sitemap\Contracts\Sitemapable;
use Spatie\Sitemap\Tags\Url;

class Post extends Model implements Sitemapable
{
public function toSitemapTag(): Url | string | array
{
return Url::create(route('blog.post.show', $this))
->setLastModificationDate(Carbon::yesterday())
->setChangeFrequency(Url::CHANGE_FREQUENCY_YEARLY)
->setPriority(0.1);
}
}

might show people quickly that they can infact easily change this per model, even adding in some model specific logic if need be.

Just a thought.

Kind regards

Elwin Bergsma