Complete milestone p3.4.0-v0.1.0 and submit to DefinitelyTyped

[AGBrown]

Needs:

• Complete items in milestones/p3.4.0-v0.1.0
• Review pouchdb versions. p3.4.0-v0.1.0 should correspond to v3.4.0 - any new features for later pouchdb versions should be appropriately branched, labelled, versioned in this repo
• Review DefinitelyTyped for recent changes to the DT Contribution guide
• Create v3.4.0 branch from master
• Create v3.4.0-v0.1.0 tag on v3.4.0 branch
• Create release with the appropriate file and folder structure for DefinitelyTyped and create PR through DefinitelyTyped-ABContrib relating to A refreshed d.ts for pouchdb v.3.4.0+, and v4.0.0+ DefinitelyTyped/DefinitelyTyped#4328
• Update A refreshed d.ts for pouchdb v.3.4.0+, and v4.0.0+ DefinitelyTyped/DefinitelyTyped#4328 with relevant info
• Advertise release