This is great, George! I made some edits with the following themes:
Strengthened the intro a bit by making reference to data journalism and leading with the pitch/goals of Muck rather than the functionality.
Added a few references to data journalism throughout to make our inspiration and main intended users more obvious, and to help people understand our aims more through the analogy.
Simplified sentence structures for clarity.
Changed 'checks' to 'tests' in the testing section to make it slightly easier to understand for those who are already familiar with TDD.
This is great, George! I made some edits with the following themes: