Integrate a documentation linter to improve readability

[busykoala]

Is your feature request related to a problem? Please describe.
The documentation is crucial to the users of this package. It is important to continuously work on the documentation and make it as readable as possible.

Describe the solution you'd like
One way to improve upon the documentation is to follow some guidelines.
Vale provides some great templates to integrate with widely used guidelines and check them for documentation files.

Describe alternatives you've considered
There are many other solutions on the market while Vale addresses and combines some of the most important topics (general guidelines, naive linting, readability, sexism, etc.).