Roadmap to a v1.0.0

This is a lovely little package. So useful!

In recent months it's move into the JuliaDiff org, been renamed for discoverability (by popular demand!), and become the corner stone for testing other JuliaDiff packages (not least ChainRules.jl).

Perhaps it is time to think about a v1.0?

From https://semver.org/

Major version zero (0.y.z) is for initial development. Anything MAY change at any time. The public API SHOULD NOT be considered stable.

Version 1.0.0 defines the public API. The way in which the version number is incremented after this release is dependent on this public API and how it changes.

Roughly speaking, a major release is saying that we are happy enough with the current API to keep supporting it and don't intended to make any breaking changes to it in, say, the next year or so. In return, users can get all new features "for free" without having to keep opting in to each new 0.y release.

• some open issues are specifically concerning the API, e.g. #35,
• some feature requests, e.g. #1, #2, are significant enough that they may make us rethink some APIs?
• others I do not know e.g. #24

Any issues that fit the bill can be tagged with the v1 milestone.

This is an issue so we can discuss these things and make sure we get to v1.

Start by reviewing the discussion and the referenced issues #35, #1, #2, and #24, then inspect the linked v1 milestone. Determine which API or feature questions must be resolved before v1. Done means the scope and compatibility expectations are agreed, relevant issues are identified, and the project has a clear path to the v1 release.