README doesn't actually work...

```python
from pyserini.encode import JsonlCollectionIterator
from pyserini.encode.optional import FaissRepresentationWriter
from uniir_for_pyserini.uniir_corpus_encoder import CorpusEncoder
```

Actually, shouldn't the final line be?

```python
from uniir_for_pyserini.pyserini_integration.uniir_corpus_encoder import CorpusEncoder
```