Make underscores same length as title

Author: bastbu

docs/exporter/prometheus/prometheus.rst

@@ -48,7 +48,7 @@ The following environment variables are supported:
 * ``OTEL_EXPORTER_PROMETHEUS_PORT`` (default: 9464): The port to bind to
 
 Limitations
------------------
+-----------
 
 * No multiprocessing support: The Prometheus exporter is not designed to operate in multiprocessing environments (see `#3747 <https://github.com/open-telemetry/opentelemetry-python/issues/3747>`_).
 

exporter/opentelemetry-exporter-prometheus/README.rst

@@ -16,7 +16,7 @@ Installation
      pip install opentelemetry-exporter-prometheus
 
 Limitations
------------------
+-----------
 
 * No multiprocessing support: The Prometheus exporter is not designed to operate in multiprocessing environments (see `#3747 <https://github.com/open-telemetry/opentelemetry-python/issues/3747>`_).