Log correlation/redaction doc improvements

[reyang]

1. Updated the log correlation example to follow the best practices.
2. Added placeholders for enrichment and filtering to the logging best practice doc.
3. Added log correlation and redaction to the logging best practice doc.

[codecov]

Codecov Report

Attention: 16 lines in your changes are missing coverage. Please review.

Comparison is base (6250307) 83.38% compared to head (a59ebd5) 83.01%.
Report is 33 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5262      +/-   ##
==========================================
- Coverage   83.38%   83.01%   -0.37%     
==========================================
  Files         297      272      -25     
  Lines       12531    11983     -548     
==========================================
- Hits        10449     9948     -501     
+ Misses       2082     2035      -47     

Flag	Coverage Δ
unittests	?
unittests-Solution-Experimental	82.77% <36.00%> (?)
unittests-Solution-Stable	83.01% <36.00%> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
...etryProtocol/Implementation/ExperimentalOptions.cs	100.00% <ø> (ø)
...tation/OpenTelemetryProtocolExporterEventSource.cs	100.00% <100.00%> (ø)
...rotocol/Implementation/OtlpLogRecordTransformer.cs	93.45% <100.00%> (ø)
...tation.AspNetCore/Implementation/HttpInListener.cs	89.72% <100.00%> (+0.14%)	⬆️
...AspNetCore/Implementation/HttpInMetricsListener.cs	89.47% <ø> (ø)
...plementation/HttpWebRequestActivitySource.netfx.cs	80.77% <100.00%> (ø)
...emetry/Metrics/Exemplar/SimpleExemplarReservoir.cs	80.43% <100.00%> (ø)
...mentation/Retry/OtlpExporterTransmissionHandler.cs	0.00% <0.00%> (ø)

... and 32 files with indirect coverage changes

[CodeBlanch]

LGTM