What are some alternatives?
When comparing MkDocs and ElasticSearch, you can also consider the following products
GitBook - Modern Publishing, Simply taking your books from ideas to finished, polished books.
Algolia - Algolia's Search API makes it easy to deliver a great search experience in your apps & websites. Algolia Search provides hosted full-text, numerical, faceted and geolocalized search.
ReadTheDocs - Spend your time on writing high quality documentation, not on the tools to make your documentation work.
Apache Solr - Solr is an open source enterprise search server based on Lucene search library, with XML/HTTP and...
Sphinx Search - Sphinx is an open source full text search server, designed with performance, relevance (search quality), and integration simplicity in mind. Sphinx lets you either batch index and search data stored in files, an SQL database, NoSQL storage.
Swiftype - The simplest way to add search to your website or application. Sign up for free.