Update petstore examples.

[kylehodgetts]

Correct flags to use periods and not dashes. Write quick start examples for Linkerd and Nginx Ingress

Changes

• Old example flags converted to new form
• Added additional quick start example for Linkerd and Nginx Ingress

Checklist

• [x] tested locally
• [ ] added new dependencies
• [x] updated the docs
• [ ] added a test