documentation: "OPTIONAL db" as remote url to query couchDB

[BananaAcid]

It would be wonderful, to have a few lines in the readme, about "OPTIONAL db"

• is stored in $databases (be aware: URL is the key, if using login and not prepended credentials, the urls result in the same key)
• if isRemote, it will "bypass" the pouchdb (which is also referenced in defaultDB) and query that remote couchdb instance (or what ever it's adapter does)
• is useful to query the remote instance directly, if synced partially
• is useful to get the data storage size
• can be used in pouch: remoteDBRef() { database: this.$databases.filter( e=>e._remote ).pop() } (or something along those lines)

I think, that would also make it a fine access tool to CouchDB, in case of caching or generating non sync-able stuff locally. For me at least.

Btw: Great intermediate Pouch-lib ! As a vue-lib - it is a real timesaver as well as keeping code short and clean! Thanks!