Fix example command for enabling feature gates (#2391)

Signed-off-by: Artem Nefedov <requiem1337@gmail.com>

README.md

@@ -538,7 +538,7 @@ OpenTelemetry Operator allows to instrument multiple containers using multiple l
 These features can be enabled using `operator.autoinstrumentation.multi-instrumentation` flag when installing the Operator via Helm. By default flag is `disabled`. For example:
 
 ```sh
-helm install opentelemetry-operator open-telemetry/opentelemetry-operator --set manager.featureGates=operator.autoinstrumentation.multi-instrumentation=enabled
+helm install opentelemetry-operator open-telemetry/opentelemetry-operator --set manager.featureGates=operator.autoinstrumentation.multi-instrumentation
 ```
 
 For more information about multi-instrumentation feature capabilities please see [Multi-container pods with multiple instrumentations](#Multi-container-pods-with-multiple-instrumentations).