v1.0 Roadmap

It would be nice to create list of high-priority tasks to compete until 1.0 release. We could discuss it's content and put our efforts to complete this list, stabilize client API and release v1.0.

I believe it would help to regulate finch needs and priorities, making it more mature in all terms.

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- [x] Respond multiple content-types per coproduct endpoint (see #575, #583, and #794)
- [x] `finch-generic`, a standalone package providing generic derivation (see #528)
- [x] JSON streaming request (see #336, #557, and #812).
- [ ] Figure out whether or not to keep `ValidationRule` (see #513)
- [ ] Better API for `io.finch.items` (see #529)
- [x] Decode JSON directly from `Buf` (see #511)
- [ ] Better story for `Encode.*[Exception]` (see #547, [Finch No Exceptions](https://gist.github.com/vkostyukov/6192a5280e485661d3d5f88dd5899f54))
- [ ] ADT representing `Endpoint`s metadata (see #581).
- [x] Reduce the performance gap between Finagle/Finch to 5%

Start by reviewing the unchecked roadmap items and their linked issues (#513, #529, #547, and #581), then compare them with the completed work and the stated API-stability goal. Done means the project has an agreed, prioritized set of 1.0 tasks with clear status and release scope.

Written by the indexing model from the issue text.