By default, a prefix matching strategy is still used but it can be overridden like so:

```js
import SearchApi, { INDEX_MODES } from 'js-worker-search'

// all-substrings match by default; same as current
// eg "c", "ca", "a", "at", "cat" match "cat"
const searchApi = new SearchApi()

// prefix matching (eg "c", "ca", "cat" match "cat")
const searchApi = new SearchApi({
  indexMode: INDEX_MODES.PREFIXES
})

// exact words matching (eg only "cat" matches "cat")
const searchApi = new SearchApi({
  indexMode: INDEX_MODES.EXACT_WORDS
})
```