bug: WeaviateDocumentIndex fails if index name is not capitalized #1709

from docarray import BaseDoc, DocList
from docarray.index import WeaviateDocumentIndex
from docarray.typing import NdArray
from pydantic import Field
import numpy as np

# Define the document schema.
class MyDoc(BaseDoc):
    title: str
    embedding: NdArray[128] = Field(is_embedding=True)

# Create dummy documents.
docs = DocList[MyDoc](MyDoc(title=f'title #{i}', embedding=np.random.rand(128)) for i in range(10))

# Initialize a new WeaviateDocumentIndex instance and add the documents to the index.
doc_index = WeaviateDocumentIndex[MyDoc](index_name='zdzd')
doc_index.index(docs)

# Perform a vector search.
query = np.ones(128)
retrieved_docs = doc_index.find(query, limit=10)