broken markdown in README

1. tables show as `preformatted` (like [#attributes](https://github.com/algolia/algoliasearch-client-java/tree/e294da4ba77a02dd200a4f63e65197d54772687b#attributes))
2. Missing title in some places (like [#missing-title](https://github.com/algolia/algoliasearch-client-java/tree/e294da4ba77a02dd200a4f63e65197d54772687b#missing-title))