Fix link to setup facets and measures

[louiszawadzki]

What does this PR do?

Fix broken link in documentation.

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• Make sure you discussed the feature or bugfix with the maintaining team in an Issue
• Make sure each commit and the PR mention the Issue number (cf the CONTRIBUTING doc)

[codecov-commenter]

Codecov Report

Merging #1179 (ad5bd52) into master (d2caeca) will decrease coverage by 0.13%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #1179      +/-   ##
==========================================
- Coverage   83.19%   83.06%   -0.13%     
==========================================
  Files         274      274              
  Lines        9458     9458              
  Branches     1540     1540              
==========================================
- Hits         7868     7856      -12     
- Misses       1153     1156       +3     
- Partials      437      446       +9     

Impacted Files	Coverage Δ
...main/java/com/datadog/exec/CommonTaskExecutor.java	45.83% <0.00%> (-4.17%)	⬇️
...g/internal/domain/event/DdSpanToSpanEventMapper.kt	96.15% <0.00%> (-3.85%)	⬇️
...ndroid/telemetry/internal/TelemetryEventHandler.kt	68.75% <0.00%> (-3.57%)	⬇️
...android/rum/internal/ndk/DatadogNdkCrashHandler.kt	85.41% <0.00%> (-3.24%)	⬇️
.../android/rum/internal/monitor/DatadogRumMonitor.kt	92.78% <0.00%> (-0.56%)	⬇️
...rc/main/java/com/datadog/opentracing/DDTracer.java	56.07% <0.00%> (+0.42%)	⬆️
...ndroid/core/internal/persistence/file/EventMeta.kt	90.00% <0.00%> (+10.00%)	⬆️