feat(instrumentation): Add litellm package instrumentation (#4322)

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: galzilber

packages/opentelemetry-instrumentation-litellm/README.md

@@ -0,0 +1,33 @@
+# OpenTelemetry LiteLLM Instrumentation
+
+<a href="https://pypi.org/project/opentelemetry-instrumentation-litellm/">
+    <img src="https://badge.fury.io/py/opentelemetry-instrumentation-litellm.svg">
+</a>
+
+This library allows tracing LLM prompts and completions sent with [LiteLLM](https://github.com/BerriAI/litellm). Because LiteLLM normalizes every provider's reply into an OpenAI-style `ModelResponse` — including custom providers registered via `litellm.CustomLLM` — a single set of wrappers produces consistent `gen_ai.*` spans and metrics across all back-ends.
+
+## Installation
+
+```bash
+pip install opentelemetry-instrumentation-litellm
+```
+
+## Example usage
+
+```python
+from opentelemetry.instrumentation.litellm import LiteLLMInstrumentor
+
+LiteLLMInstrumentor().instrument()
+```
+
+## Privacy
+
+**By default, this instrumentation logs prompts, completions, and embeddings to span attributes**. This gives you a clear visibility into how your LLM application is working, and can make it easy to debug and evaluate the quality of the outputs.
+
+However, you may want to disable this logging for privacy reasons, as they may contain highly sensitive data from your users. You may also simply want to reduce the size of your traces.
+
+To disable logging, set the `TRACELOOP_TRACE_CONTENT` environment variable to `false`.
+
+```bash
+TRACELOOP_TRACE_CONTENT=false
+```