[Issue] Change Remote Containers badge in templates to Dev Container

[jongio]

Remote containers was rebranded Dev Containers.

Our templates have

Would be good to update to this style

[![Open in GitHub Codespaces](https://img.shields.io/static/v1?style=for-the-badge&label=GitHub+Codespaces&message=Open&color=lightgrey&logo=github)](https://codespaces.new/azure-samples/openai-plugin-fastapi)
[![Open in Dev Container](https://img.shields.io/static/v1?style=for-the-badge&label=Dev+Container&message=Open&color=blue&logo=visualstudiocode)](https://vscode.dev/redirect?url=vscode://ms-vscode-remote.remote-containers/cloneInVolume?url=https://github.com/azure-samples/openai-plugin-fastapi)

[savannahostrowski]

@rajeshkamal5050 Super low hanging fruit

[rajeshkamal5050]

@vhvb1989 can we get the template readme's updated?