Narwhals v1.15.0

Changes

✨ Enhancements

• feat: consistently return Python scalars from Series reductions for PyArrow (#1471)
• feat: make Series generic (#1412)
• feat: create dataframe from 2D numpy array and column names (#1456)
• feat: diagonal concat (#1455)

🐞 Bug fixes

• fix: address lit broadcasting and output name of right arithmetic ops (#1424)

📖 Documentation

• docs: clean lazyframe docstrings (#1466)
• docs: ecosystem and resources (#1468)
• docs: add from/to_native in documentation examples (#1461)

🛠️ Other improvements

• ci: Remove vegafusion from blocking releases, assert current branch in bump_version (#1470)
• chore: PyArrow type hinting (#1465)
• ci: add hierarchicalforecast (#1460)

Thank you to all our contributors for making this release possible!
@AlessandroMiola, @EdAbati, @FBruzzesi, @MarcoGorelli and @raisadz