docs(ts): fix some d.ts

[atian25]

Checklist

• npm test passes
• tests and/or benchmarks are included
• documentation is changed or added
• commit message follows commit guidelines

Affected core subsystem(s)

Description of change

• close egg ts ctx.request.body #2137
• doc fix

[shepherdwind]

😅，这个我也改了一些。我先发一个 mr 到这个分支 #2145

[codecov-io]

Codecov Report

Merging #2144 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #2144   +/-   ##
=======================================
  Coverage   99.59%   99.59%           
=======================================
  Files          29       29           
  Lines         743      743           
=======================================
  Hits          740      740           
  Misses          3        3

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