INSERT with CTE

`ts
const entities = [
  ["My first post", "my-first-post"],
  ["My second post", "my-second-post"],
];

await db.execute(sql`
  WITH
  "input" ("title", "slug") AS (
    VALUES
      ${sql.join(entities, sql`, `)}
  ),
  "new" AS (
    INSERT INTO ${schema.entities} ("slug")
    SELECT "slug"
    FROM "input"
    RETURNING "id", "slug"
  )
  INSERT INTO ${schema.posts} ("id", "title")
  SELECT "new"."id", "input"."title"
  FROM "new"
  JOIN "input" USING ("slug");
`);