update readme
update readme

[skip ci]

seigel/pouchdb,cdaringe/pouchdb,seigel/pouchdb,pouchdb/pouchdb,cdaringe/pouchdb,pouchdb/pouchdb,cdaringe/pouchdb,seigel/pouchdb,tyler-johnson/pouchdb,pouchdb/pouchdb,tyler-johnson/pouchdb,tyler-johnson/pouchdb