readme textual wget readme fix

[echads]

[ONNXRuntimeError] : 3 : NO_SUCHFILE : Load model from textual.onnx failed:Load model textual.onnx failed. File doesn't exist

Typo in README.md

https://clip-as-service.s3.us-east-2.amazonaws.com/models/onnx/ViT-L/14/textual.onnx

should be:

https://clip-as-service.s3.us-east-2.amazonaws.com/models/onnx/ViT-L-14/textual.onnx

A "/" was used instead of a "-"

• It is also one of the first things the readme says to do.