Merge pull request #28 from a5ob7r/fix_typo

Fix a typo in README

README.md

@@ -7,7 +7,7 @@ You write a single instance, of the 'Codec' type-class, for your type, and you g
 
 * [A 'ToJSON' instance from 'aeson' with both a `toJSON` and `toEncoding` implementation](https://hackage.haskell.org/package/aeson-2.0.1.0/docs/Data-Aeson-Types.html#t:ToJSON)
 * [A 'FromJSON' instance from 'aeson'](https://hackage.haskell.org/package/aeson-2.0.1.0/docs/Data-Aeson-Types.html#t:FromJSON)
-* [A 'ToYaml` instance from 'yaml'](https://hackage.haskell.org/package/yaml-0.11.7.0/docs/Data-Yaml-Builder.html#t:ToYaml)
+* [A 'ToYaml' instance from 'yaml'](https://hackage.haskell.org/package/yaml-0.11.7.0/docs/Data-Yaml-Builder.html#t:ToYaml)
 * [A json schema](http://json-schema.org/)
 * [A nicely-coloured human-readable yaml schema](./autodocodec-yaml)
 * [A Swagger schema](https://swagger.io/specification/v2/)