add example for using oras CLI container as locally installed application

[qweeah]

In current documentation, there is an example of using oras container as locally installed application.

docker run -it --rm -v $(pwd):/workspace ghcr.io/oras-project/oras:v0.16.0 help

We can remove -v $(pwd):/workspace since oras help won't use it, and add more examples like push or pull to show amazing work oras container can do with mounting.

[qweeah]

cc @FeynmanZhou

[FeynmanZhou]

Thanks. I will create a PR to update the whole installation guide.
@qweeah Can you clarify why we need to add examples like push or pull to the installation guide?

[qweeah]

I didn't mean we should add push and pull to the installation guide. They should be added to an ad-hoc doc to show how oras container can be used just like a locally installed application.