Improves docs

Author: sobolevn

CHANGELOG.md

@@ -7,6 +7,7 @@ We follow Semantic Versions since the `0.1.0` release.
 
 ### Features
 
+- Adds `mypy` plugin to type decorators
 - Complete rewrite of `Result` types
 - Partial API change, now `Success` and `Failure` are not types, but functions
 - New internal types introduced: `FixableContainer` and `ValueUnwrapContainer`

CONTRIBUTING.md

@@ -6,6 +6,7 @@ If you want to start working on this project,
 you will need to get familiar with these concepts:
 
 - http://learnyouahaskell.com/functors-applicative-functors-and-monoids
+- https://github.com/dbrattli/OSlash/wiki/Functors,-Applicatives,-And-Monads-In-Pictures
 
 Here are some practical examples of what we are doing here:
 
@@ -53,7 +54,7 @@ We use `mypy` to run type checks on our code.
 To use it:
 
 ```bash
-mypy returns
+mypy returns tests/**/*.py
 ```
 
 This step is mandatory during the CI.

README.md

@@ -27,7 +27,7 @@ pip install returns
 You might also need to [configure](https://returns.readthedocs.io/en/latest/pages/container.html#type-safety)
 `mypy` correctly and install our plugin:
 
-```cfg
+```ini
 [mypy]
 plugins =
   returns.contrib.mypy.decorator_plugin

docs/pages/container.rst

@@ -273,6 +273,12 @@ since they increase your developer experience and type-safety:
 
 - ``decorator_plugin`` to solve untyped `decorator issue <https://github.com/python/mypy/issues/3157>`_
 
+.. code:: ini
+
+  [mypy]
+  plugins =
+    returns.contrib.mypy.decorator_plugin
+
 You can have a look at the suggested ``mypy``
 `configuration <https://github.com/dry-python/returns/blob/master/setup.cfg>`_
 in our own repository.