Fix typo (#3656)

Author: ftnext

instrumentation-genai/opentelemetry-instrumentation-google-genai/examples/zero-code/README.rst

@@ -2,7 +2,7 @@ OpenTelemetry Google GenAI SDK Manual Instrumentation Example
 ============================================
 
 This is an example of how to instrument Google GenAI SDK calls with zero code changes,
-using `opentelemetryh-instrument`.
+using `opentelemetry-instrument`.
 
 When `main.py <main.py>`_ is run, it exports traces, logs, and metrics to an OTLP
 compatible endpoint. Traces include details such as the model used and the