README fixes and tweaks (#60)
README fixes and tweaks (#60)

* README fixes and tweaks

* Added a link to the "TypeScript integration" section.
* Reordered arrays, dictionaries to be grouped together.
* Removed `maybe`, it's no longer supplied (since 0.2.2).
* Added `interface inheritance`.
* Added a link to the "TypeScript integration" section to the recursive
types in the table (there is an example for `recursion`).
* Reordered `refinement` to the end, closer to other types unsupported
by TypeScript.
* Added explanation what is `maybe` in its example.

Refs https://github.com/gcanti/io-ts/issues/59

* README heading for recursive types

gcanti/io-ts,gcanti/io-ts