[DOC] Add section on commit tagging to CONTRIBUTING.md

[courajs]

2 questions:

• Does ember data use feature flags in the same way as ember.js?
• I left "submit your PR against emberjs:master", since people's remote in their data repo may be named emberjs. I could also change it to data:master

[courajs]

For #4238

[pangratz]

Maybe we should use An ember-data contributor will let ... here

[pangratz]

Does ember data use feature flags in the same way as ember.js?

Basically yes, the only difference is that isEnabled is imported from ember-data/-private/features;

I left "submit your PR against emberjs:master", since people's remote in their data repo may be named emberjs. I could also change it to data:master

What do you think of changing this to "submit your PR against the master branch of https://github.com/emberjs/data"? I think this should be clear enough where to create PR to...

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Thank you so much @courajs for helping out here. Much appreciated!!!

@bmac @fivetanley since you are the masters of release ceremony, can you take a look here?

[courajs]

I opted to just say "against the master branch.", unless you think the url is useful.
They are reading this on the proper repo, after all

[bmac]

Looks great. Thanks @courajs