Add package which gives ability compile check and execute code provided in documentation

[crupley]

Problem
Outdated code examples or even mistakes in syntax in documentation can cause confusion when users do not get the same results when trying to run the code shown.

Solution

• Would like to add a dependency for scalatest mdoc which can generate documentation with compiled and executed scala code.
• This will also require updating any documentation where the project would be taking advantage of this feature.

Alternatives
One alternative is tut which has similar functionality, but does not provide as clear error messages when the documentation code fails to compile.

Additional context
none

[crupley]

May be an issue that mdoc only supports scala 2.12 currently.