Fix README gaps, extract main(), add package init files, document optional env vars

[Copilot]

The repo had a broken setup guide, missing Python package structure, and undocumented configuration options.

Changes

README

• Step 1 was an empty backtick with no command — added the git clone invocation
• Fixed "environemnt" typo; renumbered steps (5 → 7 skipped step 6)

main.py

Extracted if __name__ == "__main__" block into a main() function, enabling the program to be imported and composed into other contexts (e.g. a web app):

def main():
    cluster = connect_to_couchbase_cluster()
    vector_store = initialize_vector_store(cluster)
    generate_and_store_embeddings(cluster, vector_store)
    # ... interactive CLI loop ...

if __name__ == "__main__":
    main()

Also removed the unused collection variable that was left in the old block.

Package structure

Added empty src/__init__.py and src/search/__init__.py so both directories are recognized as proper Python packages.

.env.sample

Added all five optional config overrides as commented-out entries so users know what can be tuned without reading config.py:

# EMBEDDING_MODEL_NAME=sentence-transformers/all-mpnet-base-v2
# VECTOR_INDEX_NAME=travel_inventory_hotel_hugging_face_vector_index
# VECTOR_FIELD_NAME=description_minilm_vector
# MODEL_DIMENSIONS=768
# FTS_INDEX_NAME=travel_inventory_hotel_fts_index