fix(module:descriptions): fix DOM structure

[wzhudev]

close #6109

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/NG-ZORRO/ng-zorro-antd/blob/master/CONTRIBUTING.md#commit
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

[x] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[ ] Documentation content changes
[ ] Application (the showcase website) / infrastructure changes
[ ] Other... Please describe:

What is the current behavior?

Issue Number: N/A

What is the new behavior?

Does this PR introduce a breaking change?

[x] Yes
[ ] No

Other information

[codecov]

Codecov Report

Merging #6112 (b170bf8) into master (167bf15) will increase coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #6112      +/-   ##
==========================================
+ Coverage   89.84%   89.85%   +0.01%     
==========================================
  Files         465      465              
  Lines       14095    14095              
  Branches     2236     2236              
==========================================
+ Hits        12663    12665       +2     
+ Misses        881      878       -3     
- Partials      551      552       +1     

Impacted Files	Coverage Δ
components/descriptions/descriptions.component.ts	100.00% <ø> (ø)
components/core/util/text-measure.ts	89.56% <0.00%> (-1.74%)	⬇️
components/table/src/table-data.service.ts	84.61% <0.00%> (+6.15%)	⬆️

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