Update otlp-exporter.md (#5063)

Co-authored-by: Phillip Carter <[email protected]>
Co-authored-by: Tiffany Hrabusa <[email protected]>

Author: 3 people

content/en/docs/languages/sdk-configuration/otlp-exporter.md

@@ -162,9 +162,12 @@ The timeout value for all outgoing logs in milliseconds.
 
 **Example:** `export OTEL_EXPORTER_OTLP_LOGS_TIMEOUT=500`
 
-### `OTEL_EXPORTER_OTLP_PROTOCOL`
+## Protocol configuration
+
+The following environment variables configure the OTLP transport protocol
+an OTLP exporter uses.
 
-## Protocol Configuration
+### `OTEL_EXPORTER_OTLP_PROTOCOL`
 
 Specifies the OTLP transport protocol to be used for all telemetry data.