Support decimal number

[pingan1927]

First of all, thanks for your contribution! :-)

Please makes sure these boxes are checked before submitting your PR, thank you!

• Make sure you follow antd's code convention.
• Run npm run lint and fix those errors before submitting in order to keep consistent code style.
• Rebase before creating a PR to keep commit history clear.
• Add some descriptions and refer relative issues for you PR.

[mention-bot]

@pingan1927, thanks for your PR! By analyzing the history of the files in this pull request, we identified @yiminghe, @silentcloud and @warmhug to be potential reviewers.

[codecov]

Codecov Report

Merging #1231 into master will decrease coverage by 0.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #1231      +/-   ##
==========================================
- Coverage    69.8%   69.79%   -0.02%     
==========================================
  Files         219      219              
  Lines        4150     4155       +5     
  Branches     1223     1225       +2     
==========================================
+ Hits         2897     2900       +3     
- Misses       1252     1254       +2     
  Partials        1        1

Flag	Coverage Δ
#rn	72.02% <ø> (ø)	⬆️
#web	67.51% <100%> (-0.02%)	⬇️

Impacted Files	Coverage Δ
components/input-item/index.web.tsx	60.74% <100%> (-0.04%)	⬇️

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