Add type declarations

[paolobueno]

Motivation

With type declarations we can get a lot of useful information mostly in the inferred props for warped components.

WARN: this needs https://github.com/cyclejs/cyclejs/pull/834, I've pushed a custom build to https://github.com/paolobueno/gitpkg-registry/releases/tag/cycle-run-v4.4.0-gitpkg but it could be someplace else.

See https://github.com/paolobueno/warped-ts-example for the test/example.

Changes

• Add typings
• Include typings in published package

Verification instructions

• This branch is available at npm install paolobueno/gitpkg-registry#warped-reducers-v1.0.5-gitpkg for testing
• See https://github.com/paolobueno/warped-ts-example for a working TS example
• Also try using this version on top of a previous one and see extra information supplied by vscode's language services