docs: fix the broken image url

[chenxsan]

This PR contains a:

• bugfix
• new feature
• code refactor
• test update
• typo fix
• metadata update

Motivation / Use-Case

I believe the current image url is broken:

Breaking Changes

Additional Info

[codecov]

Codecov Report

Merging #767 (75c7f4e) into master (1c94d00) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #767   +/-   ##
=======================================
  Coverage   89.31%   89.31%           
=======================================
  Files           6        6           
  Lines         805      805           
  Branches      247      247           
=======================================
  Hits          719      719           
  Misses         83       83           
  Partials        3        3           

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[snitin315]

Thanks!