Add production documentation link for OpenTelemetry (#8041)

This commit replaces the example text for OpenTelemetry with the
production website URL, creating one single source of truth for
instruction in a place more easily discoverable to users.

It is follow-up work from the documentation PR:

nginx/documentation#824

---------

Co-authored-by: Venktesh Shivam Patel <[email protected]>

Author: ADubhlaoich

examples/shared-examples/otel/README.md

@@ -1,82 +1,3 @@
-# Learn how to use OpenTelemetry with F5 NGINX Ingress Controller
+# Enable OpenTelemetry
 
-NGINX Ingress Controller supports [OpenTelemetry](https://opentelemetry.io/) with the NGINX module [ngx_otel_module](https://nginx.org/en/docs/ngx_otel_module.html).
-
-## Prerequisites
-
-1. Use a NGINX Ingress Controller image that contains OpenTelemetry.
-
-    - All NGINX Ingress Controller v5.1 images or later will contain support for `ngx_otel_module`.
-    - Alternatively, you follow [Build NGINX Ingress Controller](https://docs.nginx.com/nginx-ingress-controller/installation/build-nginx-ingress-controller/) using `debian-image` (or `alpine-image` or `ubi-image`) for NGINX or `debian-image-plus` (or `alpine-image-plus`or `ubi-image-plus`) for NGINX Plus.
-
-1. Enable snippets annotations by setting the [`enable-snippets`](https://docs.nginx.com/nginx-ingress-controller/configuration/global-configuration/command-line-arguments/#-enable-snippets) command-line argument to true.
-
-1. Load the OpenTelemetry module.
-
-    You need to load the module using the following ConfigMap key:
-
-    - `otel-exporter-endpoint`: sets the endpoint to export your OpenTelemetry traces to.
-
-    The following example shows how to use this to export data to an OpenTelemetry collector running in your cluster:
-
-    ```yaml
-    otel-exporter-endpoint: "http://otel-collector.default.svc.cluster.local:4317"
-    ```
-
-## Enable OpenTelemetry globally
-
-To enable OpenTelemetry globally (for all Ingress, VirtualServer and VirtualServerRoute resources), set the `otel-trace-in-http` ConfigMap key to `true`:
-
-```yaml
-otel-trace-in-http: "true"
-```
-
-## Enable or disable OpenTelemetry per Ingress resource
-
-You can use annotations to enable or disable OpenTelemetry for a specific Ingress resource. As mentioned in the prerequisites section, `otel-exporter-endpoint` must be configured.
-
-Consider the following two cases:
-
-### OpenTelemetry is globally disabled
-
-1. To enable OpenTelemetry for a specific Ingress resource, use the server snippet annotation:
-
-    ```yaml
-    nginx.org/server-snippets: |
-        otel_trace on;
-    ```
-
-1. To enable OpenTelemetry for specific paths:
-
-    - You need to use [Mergeable Ingress resources](https://docs.nginx.com/nginx-ingress-controller/configuration/ingress-resources/cross-namespace-configuration)
-    - You need to use the location snippets annotation to enable OpenTelemetry for the paths of a specific Minion Ingress resource:
-
-        ```yaml
-        nginx.org/location-snippets: |
-            otel_trace on;
-        ```
-
-### OpenTelemetry is globally enabled
-
-1. To disable OpenTelemetry for a specific Ingress resource, use the server snippet annotation:
-
-    ```yaml
-    nginx.org/server-snippets: |
-        otel_trace off;
-    ```
-
-1. To disable OpenTelemetry for specific paths:
-
-    - You need to use [Mergeable Ingress resources](https://docs.nginx.com/nginx-ingress-controller/configuration/ingress-resources/cross-namespace-configuration)
-    - You need to use the location snippets annotation to disable OpenTelemetry for the paths of a specific Minion Ingress resource:
-
-        ```yaml
-        nginx.org/location-snippets: |
-            otel_trace off;
-        ```
-
-## Customize OpenTelemetry
-
-You can customize OpenTelemetry through the supported [OpenTelemetry module directives](https://nginx.org/en/docs/ngx_otel_module.html). Use the `location-snippets` ConfigMap keys or annotations to insert those directives into the generated NGINX configuration.
-
-> Note: At present, the additional directives in the `otel_exporter` block cannot be modified with snippets.
+This is the example code used in the [Enable OpenTelemetry](https://docs.nginx.com/nginx-ingress-controller/logging-and-monitoring/opentelemetry) documentation.