Import llama_index by default in our docs/notebooks (#486)

CONTRIBUTING.md

README.md

docs/getting_started/installation.md

docs/getting_started/starter_example.md

docs/guides/usage_pattern.md

docs/guides/use_cases.md

docs/how_to/composability.md

docs/how_to/cost_analysis.md

docs/how_to/custom_llms.md

docs/how_to/custom_prompts.md

docs/how_to/data_connectors.md

docs/how_to/embeddings.md

docs/index.rst

examples/async/AsyncGPTTreeIndexDemo.ipynb

examples/async/AsyncLLMPredictorDemo.ipynb

examples/async/AsyncTreeSummarizeQueryDemo.ipynb

examples/azure_demo/AzureOpenAI.ipynb

examples/composable_indices/ComposableIndices.ipynb

examples/cost_analysis/TokenPredictor.ipynb

examples/data_connectors/DatabaseReaderDemo.ipynb