add elasticsearch-osem to integrations page

docs/community/integrations.asciidoc

@@ -73,3 +73,6 @@
 
 * https://github.com/roundscope/ember-data-elasticsearch-kit[ember-data-elasticsearch-kit]:
   An ember-data kit for both pushing and querying objects to Elasticsearch cluster
+
+* https://github.com/kzwang/elasticsearch-osem[elasticsearch-osem]:
+  A Java Object Search Engine Mapping (OSEM) for Elasticsearch