Deps + parcel as bundler + no umd

What's Changed

• chore(build): replace microbundle with parcel
• feat(build): no umd bundle breaking
• chore(package): clean up released files to make package as small as possible

// commonjs import
import * as pubSub from 'graphql-pub-sub-with-initial-value'


// esm import
import * as pubSub from 'graphql-pub-sub-with-initial-value/lib/graphql-pub-sub-with-initial-value.mjs'