Update documentation

[DavidLemayian]

The documentation for this extension could be better so let's add comments into the code as docstrings and inline where needed.

[andela-onnenanya]

Hi @DavidLemayian I will want to work on this issue, but I need some clarifications.

When you talk about documentation, is it the code documentation or the user guide? If it's the code documentation, that means I will have to check all applicable code/files and add proper documentation.

[DavidLemayian]

@andela-onnenanya This would be for the code documentation but we should definitely do both ( #27 ).

[andela-onnenanya]

Ok, I'm picking up this issue.

[andela-onnenanya]

The PR for this issue is waiting for reviews and merging.