Eleventy Activity Feed v2.0.0

• Most of the code in this repo has been moved to @11ty/import and we’re consuming that as a dependency.
• Properties in objects returned from getEntries method have changed:
  • label is now sourceLabel
  • title still exists but no longer has label as a prefix.
• This unlocks use of any source/service types in @11ty/import: https://github.com/11ty/eleventy-import#service-types