feat: add support for Meilisearch embedder settings

[mortezarajabi]

Summary

This PR adds support for defining Meilisearch index settings for embedders in Laravel Scout.

Embedders are used when implementing vector search or hybrid search in Meilisearch. These settings allow Meilisearch to automatically manage vector generation and similarity ranking using external embedding providers.

The Meilisearch PHP SDK already supports this via this PR.

Benefits

With this change, developers can define embedder configurations per index in their config/scout.php file, similar to other Meilisearch settings:

// config/scout.php

return [
    // ... other settings

    'meilisearch' => [
        'host' => env('MEILISEARCH_HOST', 'http://localhost:7700'),
        'key' => env('MEILISEARCH_KEY'),

        'index-settings' => [
            'products' => [
                'searchableAttributes' => ['name', 'description'],
                'filterableAttributes' => ['category', 'price'],

                'embedders' => [
                    'default' => [
                        'source' => 'openAi',
                        'apiKey' => env('OAI_API_KEY'),
                        'model' => 'text-embedding-3-small',
                        'dimensions' => 1536,
                        'distribution' => [
                            'mean' => 0.7,
                            'sigma' => 0.3,
                        ],
                    ],
                ],
            ],
        ],
    ],

    // ... other settings
];