crosstab

I could have swore I'd made a note somewhere along the way about how to crosstab with `zq` ... but - while it's not that hard, here's a decent SQL way to do it:

```sql
      SELECT
          coalesce(grid_type, 'Total') as _,
          SUM(CASE WHEN win = true THEN count ELSE 0 END) AS win,
          SUM(CASE WHEN win = false THEN count ELSE 0 END) AS loss
        GROUP BY _
```