model-conversion : add model card template for embeddings [no ci] (#15557)

model-conversion : add model card template for embeddings [no ci] (#15557)

* model-conversion: add model card template for embeddings [no ci]

This commit adds a separate model card template (model repository
README.md template) for embedding models.

The motivation for this is that there server command for the embedding
model is a little different and some addition information can be useful
in the model card for embedding models which might not be directly
relevant for causal models.

* squash! model-conversion: add model card template for embeddings [no ci]

Fix pyright lint error.

* remove --pooling override and clarify embd_normalize usage