docs: Add tracing tutorial with Jaeger

[cijothomas]

Trying to add few tutorial, starting with basic Tracing and Jaeger. If there is interest, I want to expand this to cover all signals and scenarios. This can be ported to opentelemetry.io/docs once we reach 1.0 stability for all signals.

[Copilot]

Pull Request Overview

This PR introduces a comprehensive tracing tutorial that demonstrates how to instrument a Rust application with OpenTelemetry and visualize traces using Jaeger. The tutorial serves as a foundational example for the broader goal of covering all OpenTelemetry signals.

• Creates a complete example application showing OpenTelemetry tracing integration with OTLP exporter
• Provides detailed documentation with step-by-step instructions for running Jaeger and viewing traces
• Sets up project structure with appropriate dependencies for OpenTelemetry tracing

Reviewed Changes

Copilot reviewed 3 out of 6 changed files in this pull request and generated 2 comments.

File	Description
examples/all-signals/src/main.rs	Implements a demo application with parent/child spans, attributes, and events
examples/all-signals/README.md	Comprehensive tutorial documentation with setup instructions and screenshots
examples/all-signals/Cargo.toml	Project configuration with OpenTelemetry dependencies

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 80.1%. Comparing base (c5fde17) to head (d227dc8).

Additional details and impacted files

@@          Coverage Diff          @@
##            main   #3071   +/-   ##
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  Coverage   80.1%   80.1%           
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  Files        126     126           
  Lines      21949   21949           
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  Hits       17603   17603           
  Misses      4346    4346           

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