ci: add docformatter in pyproject.toml

[ycexiao]

What problem does this PR address?

Closes#284

What should the reviewers do?

This PR (1) adds a docformatter block in pyproject.toml (2) applies docformatter to all files in the project.

Please check the modifications.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 95.10%. Comparing base (9a9f4a1) to head (df988d7).
Report is 20 commits behind head on migration.

Additional details and impacted files

@@ Coverage Diff @@## migration #285 +/- ## ========================================== Coverage 95.10% 95.10% ========================================== Files 23 23 Lines 1123 1123 ========================================== Hits 1068 1068 Misses 55 55 

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[ycexiao]

@sbillinge, it's ready for review.