Sphinx can't generate html for static abstract propert docstring

**Description of the error**
`ConfigurationReader` has a static abstract property `extension` which has a docstring.

**Describe the expected result**
Sphinx should generate html from this docstring.

**Describe the actual result**
Sphinx uses the docstring from ``staticmethod`` instead:

```
abstract property extension
staticmethod(function) -> method

Convert a function to be a static method.

A static method does not receive an implicit first argument. To declare a static method, use this idiom:

class C:
@staticmethod def f(arg1, arg2, …):

…

It can be called either on the class (e.g. C.f()) or on an instance (e.g. C().f()). The instance is ignored except for its class.

Static methods in Python are similar to those found in Java or C++. For a more advanced concept, see the classmethod builtin.
```

**Suggested fix**