Track Code of Conduct

[caseywatts]

I was just doing a survey of these with a coworker and discovered that 9/10 of the most popular addons do not have a Code of Conduct. It would be really impactful if Ember Observer tracked this :)

We made a quick gist of what we found:
https://gist.github.com/caseywatts/078c3e3c27639514ba3e5a9e50b7521a

Two ideas

• link to the code of conduct directly from the addon's show page
• incorporate presence of code of conduct into the score (if it doesn't already do that)