Add README.md

README.md

+# Elastic Search Middleware
+
+This provides an interface between Elasticsearch and the standard request format as defined by the [Related Items project]().
+
+Get up and running quickly with the [docker image](https://hub.docker.com/repository/docker/fwelter/elastic-search-middleware).
+
+If your Elasticsearch instance is not running locally at the standard port, specifiy your endpoint by
+setting the environment variable `ES_HOST`.
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