docs: change images-service to nydus

[Desiki-high]

Relevant Issue (if applicable)

Since #1405, we had changed repo name to nydus.

Details

Please describe the details of PullRequest.

Types of changes

What types of changes does your PullRequest introduce? Put an x in all the boxes that apply:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation Update (if none of the other choices apply)

Checklist

Go over all the following points, and put an x in all the boxes that apply.

• I have updated the documentation accordingly.
• I have added tests to cover my changes.

[codecov]

Codecov Report

Merging #1459 (5b5ece2) into master (55bba9d) will increase coverage by 0.00%.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #1459   +/-   ##
=======================================
  Coverage   44.37%   44.37%           
=======================================
  Files         123      123           
  Lines       38896    38896           
  Branches    38896    38896           
=======================================
+ Hits        17259    17261    +2     
+ Misses      20696    20695    -1     
+ Partials      941      940    -1     

see 3 files with indirect coverage changes

[adamqqqplay]

LGTM

[imeoer]

LGTM! Thanks for the PR!