fix grammar in readme.
fix grammar in readme.

rnewson/couchdb-lucene,rnewson/couchdb-lucene,ehealthafrica-ci/couchdb-lucene,eHealthAfrica/couchdb-lucene,eHealthAfrica/couchdb-lucene,ehealthafrica-ci/couchdb-lucene,ehealthafrica-ci/couchdb-lucene,eHealthAfrica/couchdb-lucene,rnewson/couchdb-lucene