docs: auto generate pouch cli/api docs via code

[pouchrobot]

Signed-off-by: pouchrobot pouch-dev@alibaba-inc.com

1.Describe what this PR did
This PR is automatically done by AI-based collaborating robot.
Pouchrobot will auto-generate cli/api document via https://github.com/spf13/cobra/tree/master/doc every day.

2.Does this pull request fix one issue?
None

3.Describe how you did it
First, execute command "make client" to build cli;
Second, execute command "./pouch gen-doc" to generate new cli docs.

For API part, we use a tool swagger2markup to make it.

4.Describe how to verify it
None

5.Special notes for reviews
The cli/api doc must be automatically generated.

[codecov]

Codecov Report

Merging #2571 into master will decrease coverage by 0.07%.
The diff coverage is n/a.

@@            Coverage Diff            @@
##           master   #2571      +/-   ##
=========================================
- Coverage   69.17%   69.1%   -0.08%     
=========================================
  Files         278     278              
  Lines       18623   18623              
=========================================
- Hits        12883   12869      -14     
- Misses       4268    4280      +12     
- Partials     1472    1474       +2

Flag	Coverage Δ
#criv1alpha1test	31.28% <ø> (ø)	⬆️
#criv1alpha2test	35.46% <ø> (-0.03%)	⬇️
#integrationtest	40.66% <ø> (-0.02%)	⬇️
#nodee2etest	32.6% <ø> (-0.05%)	⬇️
#unittest	26.76% <ø> (ø)	⬆️

Impacted Files	Coverage Δ
pkg/streams/utils.go	82.14% <0%> (-9.53%)	⬇️
cri/v1alpha1/cri.go	60.59% <0%> (-0.34%)	⬇️
cri/v1alpha2/cri.go	68.86% <0%> (-0.25%)	⬇️
daemon/mgr/container.go	58.79% <0%> (-0.22%)	⬇️
cri/v1alpha2/cri_wrapper.go	64.4% <0%> (ø)	⬆️

[ZYecho]

LGTM