cte-diff v0.5.0

What's Changed

• Site: a live demo in the hero, results below the diff, and qdbd.dev's motion by @MarkPhamm in #5
• Site: the playground runs real rows, with coloured editors and Preview / Compare on each CTE by @MarkPhamm in #6
• Site: how Compare sides works, in three illustrated steps instead of internal SQL by @MarkPhamm in #7
• Site: the playground gets its own page, off the landing page by @MarkPhamm in #8
• Sidebar: Compare Two Files… picks an old and a new SQL file and opens them in a diff by @MarkPhamm in #9

Full Changelog: v0.4.0...v0.5.0