Mongoose 6.3.0 发布

fix: upgrade mongodb driver -> 4.5.0 #11623 AbdelrahmanHafez

feat(schema): allow defining discriminators on schema and in schema definition #7971 IslandRhythms

feat(base): add option to set allowDiskUse globally #11554 AbdelrahmanHafez

feat(schema): add removeIndex() and clearIndex() #11547 IslandRhythms

feat(cursor): add continueOnError option to allow executing eachAsync() on all docs even if error occurs #6355

feat(query): add versionKey option to lean() for removing version key from lean docs #8934 IslandRhythms

feat(types): create new ProjectionType type for select(), find(), etc. #11437

chore: use webpack 5 for browser build #11584 AbdelrahmanHafez