Fix README.md

[robberphex]

What is the purpose of the change

fix format issue in README.md and README_ZH.md, and update npm mirror's url.

Brief changelog

Fix README.md
Fix #856

Verifying this change

Preview README.md and README_ZH.md

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• Write necessary unit-test to verify your logic correction, more mock a little better when cross module dependency exist.
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[codecov-commenter]

Codecov Report

Merging #857 (db858e0) into develop (efb7a8d) will decrease coverage by 0.10%.
The diff coverage is n/a.

@@              Coverage Diff              @@
##             develop     #857      +/-   ##
=============================================
- Coverage      21.61%   21.50%   -0.11%     
+ Complexity       428      424       -4     
=============================================
  Files            149      149              
  Lines           4683     4683              
  Branches         712      712              
=============================================
- Hits            1012     1007       -5     
- Misses          3589     3593       +4     
- Partials          82       83       +1     

Flag	Coverage Δ
unit	21.50% <ø> (-0.11%)	⬇️

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Impacted Files	Coverage Δ
...registry/mapping/impl/ZookeeperServiceMapping.java	82.35% <0.00%> (-8.83%)	⬇️
...apache/dubbo/admin/service/RegistryServerSync.java	84.72% <0.00%> (-2.78%)	⬇️

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