fix(readme): Correct urls to npm

[carlpett]

Apparent copy/paste error pointed to instrumentation-dns instead of instrumentation-express

Which problem is this PR solving?

• Wrong links

Short description of the changes

• Adjusted links to point to correct package

Checklist

• Ran npm run test-all-versions for the edited package(s) on the latest commit if applicable.

[codecov]

Codecov Report

Merging #1144 (a5fdcce) into main (bf29530) will increase coverage by 0.56%.
The diff coverage is n/a.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1144      +/-   ##
==========================================
+ Coverage   96.07%   96.63%   +0.56%     
==========================================
  Files          14       20       +6     
  Lines         892     1130     +238     
  Branches      191      245      +54     
==========================================
+ Hits          857     1092     +235     
- Misses         35       38       +3     

Impacted Files	Coverage Δ
...trumentation-express/src/enums/ExpressLayerType.ts	100.00% <0.00%> (ø)
...nstrumentation-express/src/enums/AttributeNames.ts	100.00% <0.00%> (ø)
...opentelemetry-instrumentation-express/src/types.ts	100.00% <0.00%> (ø)
...tapackages/auto-instrumentations-node/src/utils.ts	98.00% <0.00%> (ø)
...try-instrumentation-express/src/instrumentation.ts	99.29% <0.00%> (ø)
...opentelemetry-instrumentation-express/src/utils.ts	97.36% <0.00%> (ø)