docs(readme): release v1.8.2 version

[appleboy]

See the milestone: https://github.com/gin-gonic/gin/milestone/23

@thinkerou Please help to review and comments if missing another PR.

[codecov]

Codecov Report

Merging #3420 (213df54) into master (80cd679) will not change coverage.
The diff coverage is n/a.

❗ Current head 213df54 differs from pull request most recent head e0b3c5b. Consider uploading reports for the commit e0b3c5b to get more accurate results

@@           Coverage Diff           @@
##           master    #3420   +/-   ##
=======================================
  Coverage   98.27%   98.27%           
=======================================
  Files          42       42           
  Lines        3137     3137           
=======================================
  Hits         3083     3083           
  Misses         40       40           
  Partials       14       14           

Flag	Coverage Δ
	98.27% <ø> (ø)
go-1.16	∅ <ø> (∅)
go-1.17	98.18% <ø> (ø)
go-1.18	98.18% <ø> (ø)
go-1.19	98.27% <ø> (ø)
macos-latest	98.27% <ø> (ø)
ubuntu-latest	98.27% <ø> (ø)

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[appleboy]

@thinkerou Please help to review.