Docs: metrics.md file wrongly mentioned variable name to disable log

Docs mentions POWERTOOLS_METRICS_ENABLED however the library does not uses this environment variable to control metrics logs. Instead it uses POWERTOOLS_METRICS_DISABLED

Author: jorovipe97

docs/features/metrics.md

@@ -71,7 +71,7 @@ These settings will be used across all metrics emitted:
 | **Service**          | Optionally, sets **service** metric dimension across all metrics | `POWERTOOLS_SERVICE_NAME`          | `service_undefined`                                      | Any string     | `serverlessAirline` | `serviceName`         |
 | **Metric namespace** | Logical container where all metrics will be placed               | `POWERTOOLS_METRICS_NAMESPACE`     | `default_namespace`                                      | Any string     | `serverlessAirline` | `default_namespace`   |
 | **Function Name**    | Function name used as dimension for the `ColdStart` metric       | `POWERTOOLS_METRICS_FUNCTION_NAME` | [See docs](#capturing-a-cold-start-invocation-as-metric) | Any string     | `my-function-name`  | `functionName`        |
-| **Enabled**          | Whether to emit metrics to standard output or not                | `POWERTOOLS_METRICS_ENABLED`       | `true`                                                   | Boolean        | `false`             |                       |
+| **Disabled**          | Whether to disable the log of metrics to standard output or not | `POWERTOOLS_METRICS_DISABLED`       | `false`                                                   | Boolean        | `true`             |                       |
 
 !!! tip
     Use your application name or main service as the metric namespace to easily group all metrics