Add example usage to istanbul-lib-report

[lukeapage]

No description provided.

[coreyfarrell]

Thanks for starting this! Documentation in the monorepo is very much lacking, most documentation work has been on nyc itself for end-users. I have a couple comments and have requested a review by @JaKXz.

[JaKXz]

At first glance my major request is to have more descriptive variable names and even inline comments to explain the context and intent of the code and what it's doing.

Maybe another source for good examples would be jest's codebase, for inspiration :)

[coreyfarrell]

Maybe another source for good examples would be jest's codebase, for inspiration

jest is currently not a good place to look. jest is using the current version of istanbul modules. index.js on istanbuljs/nyc#1134 is probably the only code that is using the next version of istanbul-lib-report.

[lukeapage]

Fixed comments. I'm not saying this is perfect - its just I tried the alpha and updated my codebase and I ended up using the example on the refactor pr description, so I did this as I went along and made a PR so that something exists ;)

[JaKXz]

Thanks @lukeapage - I have some minor things that I think would make things clearer - writing this review as a quick set of TODOs

I'll leave this to @coreyfarell to merge.

[coreyfarrell]

@lukeapage thanks for contributing!

[Hypnosphi]

Doesn't seem to work with istanbul-lib-report@2.0.8 and istanbul-reports@2.2.6:

TypeError: reports.create(...).execute is not a function

[coreyfarrell]

@Hypnosphi that is true, these docs are for the 3.x versions (currently pre-release).