docs(readme): move Initialize Projects above the gif + add Scala to languages (#146)

- Reorder Get Started so the per-project init code block sits between
  the npx install and the GIF — visually contiguous code blocks read
  better than code → image → code.
- Add Scala (`.scala`, `.sc`) to the Supported Languages table now
  that #91 has landed.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>