Support sharding with multiple remotes (proxies)

[ellnix]

Meilisearch 1.13 adds support for multiple remotes, and we should discuss how we will support that in this gem.

[pozelli]

Perhaps the configuration could be something like this:

Meilisearch::Rails.configuration = {
  remotes: {
    'ms-01' => {
      meilisearch_url: ENV.fetch('MEILISEARCH_HOST', '...'),
      meilisearch_api_key: ENV.fetch('MEILISEARCH_API_KEY', '...'),
    },
    'ms-02' => {
      meilisearch_url: ENV.fetch('MEILISEARCH_HOST', '...'),
      meilisearch_api_key: ENV.fetch('MEILISEARCH_API_KEY', '...'),
    }
  },
  # At the moment, I don't see good reasons why one would want the options below to be inside each remote
  pagination_backend: :kaminari,
  active: true,
  timeout: 2,
  max_retries: 2
}

The search methods (in this case, federated_search) would receive the remote names and loop through them, performing the individual searches. A method to retrieve the client by name would help.