docs: auto generate pouch cli/api docs via code

[pouchrobot]

Signed-off-by: pouchrobot [email protected]

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 new pouch 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-io]

Codecov Report

Merging #1270 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #1270   +/-   ##
=======================================
  Coverage   15.21%   15.21%           
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  Files         172      172           
  Lines       10734    10734           
=======================================
  Hits         1633     1633           
  Misses       8980     8980           
  Partials      121      121

[HusterWan]

LGTM