[doc] update package level warning messages (#5608)

Co-authored-by: Mikel Blanchard <[email protected]>

Author: reyang

src/OpenTelemetry.Exporter.Console/README.md

@@ -7,9 +7,8 @@ The console exporter prints data to the Console window.
 ConsoleExporter supports exporting logs, metrics and traces.
 
 > [!WARNING]
-> This exporter is intended to be used during learning how telemetry
-data are created and exported. It is not recommended for any production
-environment.
+> This component is intended to be used while learning how telemetry data is
+  created and exported. It is not recommended for any production environment.
 
 ## Installation
 

src/OpenTelemetry.Exporter.InMemory/README.md

@@ -5,6 +5,10 @@
 
 The in-memory exporter stores data in a user provided memory buffer.
 
+> [!WARNING]
+> This component is intended to be used for testing purposes. It is
+  not recommended for any production environment.
+
 ## Installation
 
 ```shell

src/OpenTelemetry.Exporter.Prometheus.AspNetCore/README.md

@@ -7,6 +7,19 @@ An [OpenTelemetry Prometheus exporter](https://github.com/open-telemetry/opentel
 for configuring an ASP.NET Core application with an endpoint for Prometheus
 to scrape.
 
+> [!WARNING]
+> This component is still under development due to a dependency on the
+  experimental [Prometheus and OpenMetrics
+  Compatibility](https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/compatibility/prometheus_and_openmetrics.md)
+  specification and can undergo breaking changes before stable release.
+  Production environments should consider using
+  [OpenTelemetry.Exporter.OpenTelemetryProtocol](../OpenTelemetry.Exporter.OpenTelemetryProtocol/README.md).
+  Refer to the [Getting Started with Prometheus and
+  Grafana](../../docs/metrics/getting-started-prometheus-grafana/README.md)
+  tutorial for more information.
+
+<!-- This comment is to make sure the two notes above and below are not merged -->
+
 > [!NOTE]
 > This exporter does not support Exemplars. For using Exemplars, use the [OTLP
 Exporter](../OpenTelemetry.Exporter.OpenTelemetryProtocol/README.md) and use a

src/OpenTelemetry.Exporter.Prometheus.HttpListener/README.md

@@ -8,13 +8,12 @@ that configures an [HttpListener](https://docs.microsoft.com/dotnet/api/system.n
 instance for Prometheus to scrape.
 
 > [!WARNING]
-> This component is intended for dev inner-loop, there is no plan to
-make it production ready. Production environments should use
-[OpenTelemetry.Exporter.Prometheus.AspNetCore](../OpenTelemetry.Exporter.Prometheus.AspNetCore/README.md),
-or a combination of
-[OpenTelemetry.Exporter.OpenTelemetryProtocol](../OpenTelemetry.Exporter.OpenTelemetryProtocol/README.md)
-and [OpenTelemetry
-Collector](https://github.com/open-telemetry/opentelemetry-collector).
+> This component is intended for dev inner-loop, there is no plan to make it
+  production ready. Production environments should consider using
+  [OpenTelemetry.Exporter.OpenTelemetryProtocol](../OpenTelemetry.Exporter.OpenTelemetryProtocol/README.md).
+  Refer to the [Getting Started with Prometheus and
+  Grafana](../../docs/metrics/getting-started-prometheus-grafana/README.md)
+  tutorial for more information.
 
 ## Prerequisite