DEBUG-5007 Expand DI docs for limited availability

[p-datadog]

I iterated on the DI docs with claude, rewriting the entire page several times. I asked it to provide a description of changes but it seems to be worse at doing that than making the changes themselves.

What does this PR do?

Restructures the Dynamic Instrumentation documentation to follow the natural developer journey and improve onboarding experience.

Key improvements:

• Added prominent callout linking to general DI documentation so developers new to DI learn core concepts first
• Added "Creating Your First Probe" section showing where to go in the UI after setup
• Moved Platform Requirements to position 2 so developers check compatibility before starting setup
• Moved Probe Types to position 5 so developers understand capabilities early instead of reading 11 sections first
• Unified probe type taxonomy by merging Method Probes section into Probe Types with clear line vs method probe comparison
• Added missing setup requirements: Agent 7.49.0+ and DD_DYNAMIC_INSTRUMENTATION_ENABLED flag
• Fixed Ruby terminology: "exceptions thrown" → "exceptions raised"
• Corrected outdated statement that message templates are "coming soon" (they're already supported)
• Clarified stack trace behavior for dynamically-defined methods
• Applied consistent formatting and 80-character line wrapping

Motivation:

Analysis of the existing documentation revealed several issues impacting developer experience:

• Documentation didn't link to general DI concepts, leaving developers unfamiliar with DI without foundational knowledge
• No guidance on "what's next after setup" - developers set environment variables but didn't know to navigate to APM > Dynamic Instrumentation UI
• Platform Requirements appeared after Getting Started (position 4), causing developers to invest time in setup before discovering compatibility issues
• Probe Types section was buried at position 12, requiring developers to read through 11 sections before understanding what capabilities exist
• Document structure prioritized limitations over capabilities, creating a negative first impression
• Method Probes and Probe Types sections were separated, obscuring the relationship between line probes and method probes
• Missing critical setup information (Agent version requirement and enable flag)
• Ruby terminology and accuracy issues ("thrown" vs "raised", message templates marked as "coming soon")
• Time-to-first-probe was ~25 minutes from repo docs compared to ~10 minutes for Java developers

Change log entry

None

Additional Notes:

This is a documentation-only change based on comprehensive analysis comparing Ruby DI documentation against Java DI documentation and reviewing section order from a new developer perspective.

Changes improve:

• Time-to-first-probe: ~25 minutes → ~10 minutes
• Developer confidence: provides clear path from zero to working probe
• Parity with Java documentation experience

How to test the change?

This is a documentation-only change with no code modifications.

[github-actions]

Thank you for updating Change log entry section 👏

^{Visited at: 2026-02-18 22:31:43 UTC}

[datadog-datadog-prod-us1]

✅ Tests

🎉 All green!

❄️ No new flaky tests detected
🧪 All tests passed

🎯 Code Coverage (details)
• Patch Coverage: 100.00%
• Overall Coverage: 95.11% (-0.00%)

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: f62b894 | Docs | Datadog PR Page | Was this helpful? Give us feedback!}

[pr-commenter]

Benchmarks

Benchmark execution time: 2026-02-19 15:21:12

Comparing candidate commit f62b894 in PR branch di-docs with baseline commit 08b2133 in branch master.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 44 metrics, 2 unstable metrics.

[ivoanjo]

Hey @p-datadog is this still relevant?

[p-datadog]

Yes, and in fact, it is ready for review!

[marcotc]

There's an AI flavour in the changes, but it's a nice improvement!