ColBERT Wasm Demo

It would be worth to provide an example of using ColBERT passage retrieval from a user query as browser execution.
A good example has been provide [here](https://colbert.aiserv.cloud/) for query-passage score interpretability


Specifically the Contextualised Highlights gives an important overview of the inner scoring at the token level, as well as the resulting MaxSim score.

**Motivation.**
Recently I was able to benchmark ColBERT for WASM cpu execution vs. WebGPU thanks to Xenova playground [here](https://huggingface.co/spaces/Xenova/webgpu-embedding-benchmark), ColBERT (with quantization eventually) performances in the browser are efficient enough to perform passage retrieval locally with WebGPU support and eventually fallback to cpu.