indexName for Algolia DocSearch is hardcoded as 'minio'

[kaankabalak]

Currently, the indexName property in DocSearch is hardcoded as 'minio' in Doctor, which would cause the search functionality to not work for other people who don't have the same apiKey-indexName combination for the indexName 'minio'. Therefore, instead of being hardcoded, the indexName should also be configurable by the user, just like the apiKey property.