As a new contributor to the driver I've often found myself confused about the architecture of the driver, what the goals, beliefs, and directions that you expect the driver to take. There's so much context shared between developers about Go, MongoDB, and the history of the project, that it's not always obvious why some decisions were made. 

Without this kind of background I found it easy to get lost in detail, or miss the obvious solution. In addition to explaining the components of the system and an overview of their current state, it would also be useful to add some aspirational content about the direction that we want to take the driver, higher level goals, and areas of focus for the next ~year.

Having a really strong developer's guide will also help ease the cost of onboarding new contributors