Jest async example needs an await https://basarat.gitbook.io/typescript/intro-1/jest

https://basarat.gitbook.io/typescript/intro-1/jest

Following is wrong:

```
test('basic',async () => {
expect(sum()).toBe(0);
});

test('basic again', async () => {
expect(sum(1, 2)).toBe(3);
}, 1000 /* optional timeout */);
```

You need await like:

```
test('basic', async () => {
expect(await sum()).toBe(0);
});
```

Open the Jest example at https://basarat.gitbook.io/typescript/intro-1/jest and compare both async test snippets with the issue. Update the examples so the asynchronous sum call is awaited, and confirm the rendered page shows the corrected usage.

Written by the indexing model from the issue text.