docs: add adoptors.md for PouchContainer project

[allencloud]

Signed-off-by: Allen Sun allensun.shl@alibaba-inc.com

Ⅰ. Describe what this PR did

This pr adds several adopters for PouchContainer. Thanks for all the adopters.

Ⅱ. Does this pull request fix one issue?

none

Ⅲ. Describe how you did it

none

Ⅳ. Describe how to verify it

none

Ⅴ. Special notes for reviews

none

[codecov-io]

Codecov Report

Merging #2038 into master will decrease coverage by 0.16%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2038      +/-   ##
==========================================
- Coverage   63.83%   63.66%   -0.17%     
==========================================
  Files         200      200              
  Lines       15531    15531              
==========================================
- Hits         9914     9888      -26     
- Misses       4387     4409      +22     
- Partials     1230     1234       +4

Flag	Coverage Δ
#criv1alpha1test	33.77% <ø> (-0.05%)	⬇️
#criv1alpha2test	34.26% <ø> (ø)	⬆️
#integrationtest	38.26% <ø> (-0.23%)	⬇️
#unittest	22% <ø> (ø)	⬆️

Impacted Files	Coverage Δ
pkg/meta/store.go	54.76% <0%> (-4.77%)	⬇️
apis/server/utils.go	61.9% <0%> (-4.77%)	⬇️
daemon/mgr/system.go	73.5% <0%> (-3.42%)	⬇️
ctrd/image.go	79.31% <0%> (-1.98%)	⬇️
daemon/logger/jsonfile/utils.go	71.54% <0%> (-1.63%)	⬇️
daemon/containerio/container_io.go	73.48% <0%> (-1.11%)	⬇️
daemon/mgr/container_utils.go	58.72% <0%> (-0.86%)	⬇️
ctrd/container.go	51.54% <0%> (-0.69%)	⬇️
cri/v1alpha1/cri.go	65.4% <0%> (-0.19%)	⬇️
cri/v1alpha2/cri.go	66.31% <0%> (-0.18%)	⬇️
... and 2 more

[allencloud]

LGTM