README.md

## Gemini Prompt Expander

```py
from diffusers.modular_pipelines import ModularPipelineBlocks

gemini_block = ModularPipelineBlocks.from_pretrained(
    "diffusers-internal-dev/gemini-prompt-expander",
    trust_remote_code=True,
)
gemini = gemini_block.init_pipeline()
output = gemini(prompt="a dog sitting by the river, watching the sunset")
print(f"{output.values['prompt']=}")

```