[bug] CLI compatibility between Pouch and Docker

[CodeJuan]

Ⅰ. Issue Description

I found some compatibility issues of CLI, for example pouch ps doesn't support --format flag.
So I am wondering if you could provide a document of CLI compatibility and the plan of fixing compatibility issues?

Ⅱ. Describe what happened

# ./bin/pouch ps   --format "table {{.ID}}\t{{.Mounts}}"
Error: unknown flag: --format

Ⅲ. Describe what you expected to happen

same output of docker

# docker ps   --format "table {{.ID}}\t{{.Mounts}}"
CONTAINER ID        MOUNTS
082e2761b8b4        /lib/modules

Ⅳ. How to reproduce it (as minimally and precisely as possible)

Ⅴ. Anything else we need to know?

Ⅵ. Environment:

• pouch version (use pouch version):
• OS (e.g. from /etc/os-release):
• Kernel (e.g. uname -a):
• Install tools:
• Others: