[docs] dead links exist in markdown documentation

[allencloud]

Ⅰ. Issue Description

We have enabled markdown-link-check in this repo. And the result shows that the following docs have dead links:

FILE: ./docs/kubernetes/pouch_with_cri_introduction.md
[✖] https://git.k8s.io/kubernetes/pkg/kubelet/apis/cri/v1alpha1/runtime/api.proto

ERROR: dead links found!

FILE: ./docs/features/pouch_with_dragonfly.md
[✖] https://github.com/alibaba/Dragonfly/blob/master/docs/install_server.md
[✖] https://github.com/alibaba/Dragonfly/blob/master/docs/install_client.md
[✖] https://github.com/alibaba/Dragonfly/blob/master/docs/usage.md

ERROR: dead links found!

FILE: ./apis/README.md
[✖] ../docs/api/api.md

ERROR: dead links found!

FILE: ./storage/volume/README.md
[✖] ../docs/static_files/pouch_volume_architecture.png
[✖] volume/examples/demo/demo.go
[✖] docs/commandline/pouch_volume.md

This is also recorded in #2465

Ⅱ. Describe what happened

dead links exist in markdown files.

Ⅲ. Describe what you expected to happen

no dead links exist in markdown files.

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

none

Ⅴ. Anything else we need to know?

none

Ⅵ. Environment:

master code.

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

[allencloud]

cc @rudyfly @Ace-Tang
Please take a look at the dragonfly part and volume part. Thanks a lot.

[allencloud]

Could you help to handle the CRI part:? @starnop

FILE: ./docs/kubernetes/pouch_with_cri_introduction.md
[✖] https://git.k8s.io/kubernetes/pkg/kubelet/apis/cri/v1alpha1/runtime/api.proto

And you to help handle the following part? @rudyfly

FILE: ./storage/volume/README.md
[✖] ../docs/static_files/pouch_volume_architecture.png
[✖] volume/examples/demo/demo.go
[✖] docs/commandline/pouch_volume.md

[starnop]

Of course, I will do that ASAP. ^_^

[allencloud]

fixed in #2465