Reorganize APM Library Config

[brett0000FF]

What does this PR do? What is the motivation?

Add consistent section headers so library config options are easier for users to find.

Lang	Drafted	Reviewed
Java	✓
Python	✓
Go	✓
Node.js	✓
PHP	✓
C++	✓
.NET Core	✓
.NET Framework	✓

Config options are organized under the following headings, where applicable:

• Unified service tagging
• Traces
• Agent
• ASM
• Databases
• Database monitoring
• Errors
• Logs
• Profiling
• Trace context propagation

Merge instructions

• [ ] Please merge after reviewing

Additional notes

[github-actions[bot]]

Preview links (active after the build_preview check completes)

Modified Files

• https://docs-staging.datadoghq.com/brett0000FF/DOCS-7677/tracing/trace_collection/library_config/cpp
• https://docs-staging.datadoghq.com/brett0000FF/DOCS-7677/tracing/trace_collection/library_config/dotnet-core
• https://docs-staging.datadoghq.com/brett0000FF/DOCS-7677/tracing/trace_collection/library_config/dotnet-framework
• https://docs-staging.datadoghq.com/brett0000FF/DOCS-7677/tracing/trace_collection/library_config/go
• https://docs-staging.datadoghq.com/brett0000FF/DOCS-7677/tracing/trace_collection/library_config/java
• https://docs-staging.datadoghq.com/brett0000FF/DOCS-7677/tracing/trace_collection/library_config/nodejs
• https://docs-staging.datadoghq.com/brett0000FF/DOCS-7677/tracing/trace_collection/library_config/php
• https://docs-staging.datadoghq.com/brett0000FF/DOCS-7677/tracing/trace_collection/library_config/python
• https://docs-staging.datadoghq.com/brett0000FF/DOCS-7677/tracing/trace_collection/library_config/ruby

[brett0000FF]

I left some comments about section titles and inclusions using the dotnet-framework.md file for examples. I'd like to reorganize a couple of them and they likely affect all of the other pages. Besides those small number of comments, I think this is in great shape!

@zacharycmontoya - I really appreciate your review! I'll get this merged soon after I get a peer review from Docs.