docs: add EDOT SDK encouragement to index and supported-technologies (#1434)

* docs: add EDOT SDK encouragement to index and supported-technologies

Encourage users to consider the EDOT PHP SDK for observability data on the
APM agent intro and supported-technologies pages, in line with OTel adoption.

Made-with: Cursor

* docs: use EDOT SDK repo links instead of docs-content URLs

Made-with: Cursor

* Fix build error

Author: alexandra5000

docs/docset.yml

@@ -4,6 +4,7 @@ products:
 cross_links:
   - apm-agent-rum-js
   - docs-content
+  - elastic-otel-php
 toc:
   - toc: reference
   - toc: release-notes

docs/reference/index.md

@@ -14,6 +14,9 @@ applies_to:
 
 The Elastic APM PHP Agent measures the performance of your application and tracks errors. It is an extension that must be installed in your PHP environment.
 
+:::::{note}
+Elastic supports OpenTelemetry, which allows logs, metrics, and trace signal collection for many of the [supported technologies](/reference/supported-technologies.md) below. Consider using the [EDOT PHP SDK](elastic-otel-php://reference/edot-php/index.md) for observability data so you continue to get the full power of Elastic's platform.
+:::::
 
 ## Additional Components [additional-components]
 

docs/reference/supported-technologies.md

@@ -11,6 +11,10 @@ applies_to:
 
 # Supported technologies [supported-technologies]
 
+The Elastic APM PHP Agent supports the technologies listed below.
+
+Elastic supports OpenTelemetry, which allows logs, metrics, and trace signal collection for many of these technologies. Consider using the [EDOT PHP SDK](elastic-otel-php://reference/edot-php/index.md) for observability data so you continue to get the full power of Elastic's platform.
+
 If the agent doesn’t support your favorite technology yet, you can vote for it by participating in [our survey](https://docs.google.com/forms/d/e/1FAIpQLSf8c3BJVMqaeuqpq-t3_Q4NilNcdsrzK1qJ4Qo9JpJslrmYzA/viewform). We will use the results to add support for the most requested technologies.