docs: add override i18n configuration

[stygian-desolator]

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?

[ ] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[x] 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?

add content of how to override i18n configuration
#6183 (reply in thread)

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

[codecov]

Codecov Report

Merging #6195 (ef8d6d4) into master (8b92cac) will decrease coverage by 0.02%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #6195      +/-   ##
==========================================
- Coverage   89.84%   89.81%   -0.03%     
==========================================
  Files         468      468              
  Lines       14262    14262              
  Branches     2242     2242              
==========================================
- Hits        12813    12809       -4     
- Misses        894      898       +4     
  Partials      555      555              

Impacted Files	Coverage Δ
components/table/src/table-data.service.ts	78.46% <0.00%> (-6.16%)	⬇️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 8b92cac...ef8d6d4. Read the comment docs.

[hsuanxyz]

LGTM