update README

[zh-jq-b]

No description provided.

[zh-jq-b]

@eltociear I'm going to update README.md in this PR and I have updated README.ja_JP.md file by using Google Translates, can you help to check whether the translation is natural?

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 51.23%. Comparing base (5d648ea) to head (36beeb2).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #412      +/-   ##
==========================================
- Coverage   51.31%   51.23%   -0.08%     
==========================================
  Files        1091     1091              
  Lines       99651    99651              
==========================================
- Hits        51131    51061      -70     
- Misses      48520    48590      +70     

Flag	Coverage Δ
g3proxy	51.24% <ø> (-0.08%)	⬇️
lib	25.11% <ø> (ø)

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