fix(package): Allow .json extension on annotations file (issue #836)

[engelfrost]

Closes #836

Summary of changes:
Read annotations.json if it exists.
Else read annotations.js.

Not sure if being able to read the old file is a necessary convenience. If not, that part of the code (the else statement) can easily be removed.

[engelfrost]

I realized I may have misunderstood the file naming convention - when do I use _ and when do I use camelCase?

[bmuenzenmeyer]

@engelfrost thank you so much for the contribution! I will take a look at it ASAP.

I realized I may have misunderstood the file naming convention - when do I use _ and when do I use camelCase?

camelCase is my newer convention. when I started writing the app I was using underscores but have never went through and changed them all. Probably a good refactor task at some point

[bmuenzenmeyer]

@engelfrost Thank you so much my friend!