Added example for multimodal embedding

[simveit]

Motivation

Included example for multimodal embedding

Checklist

• [ x] Format your code according to the Code Formatting with Pre-Commit.
• [x ] Update documentation / docstrings / example tutorials as needed, according to Writing Documentation.

[simveit]

@zhaochenyang20 please take a look this is the example for
#3694

[zhaochenyang20]

https://github.com/simveit/sglang/tree/feature/example-multimodal-embedding/examples/runtime

Could you add one readme here to all the examples in the runtime.

[simveit]

Hello @zhaochenyang20 the latest commit introduces description of all the examples in runtime folder.