change global availability to first veruss third party

[jasonanovak]

Edits to clarify what is meant by global availability given overloading of "global" in W3C work.

See https://github.com/w3cping/blog-posts/issues/6.

[pes10k]

@jasonanovak thanks for these suggestions, but I think the proposed change narrows the suggestion more than I mean. I'd like standards authors to consider as many ways as possible of restricting functionality grown, and 1st-vs-3rd party is just one of those (permissions, user gestures, etc are others).

Is there some other change that you could suggest that would cover the emphasis you'd like to see, w/o ruling out the above suggestions?

[samuelweiler]

I'm about to ship the blog post as-is. We can apply this patch later, if we want to. New edits will need to be done directly on the blog (word press) site at: https://www.w3.org/blog/wp-admin/post.php?post=17928&action=edit

[pes10k]

Thanks @samuelweiler !