[editorial] OTLP design & req: redirect to GH & mark as external (open-telemetry#3833)

Author: chalin

specification/protocol/README.md

@@ -4,8 +4,13 @@ linkTitle: Protocol
 
 # OpenTelemetry Protocol
 
-The OpenTelemetry protocol (OTLP) specification has moved to
-[github.com/open-telemetry/opentelemetry-proto/docs/README.md](https://github.com/open-telemetry/opentelemetry-proto/blob/main/docs/README.md).
+The OpenTelemetry protocol (OTLP) design goals, requirements, and
+[specification] have moved to
+[github.com/open-telemetry/opentelemetry-proto/docs](https://github.com/open-telemetry/opentelemetry-proto/blob/main/docs/).
+
+You can also view the specification from the OpenTelemetry website, see [OTLP][specification].
 
 For additional OTLP implementation requirements in the OpenTelemetry SDKs, see
 [SDK Exporter](exporter.md).
+
+[specification]: https://opentelemetry.io/docs/specs/otlp/

specification/protocol/design-goals.md

@@ -1,5 +1,7 @@
 <!--- Hugo front matter used to generate the website version of this page:
 linkTitle: Design Goals
+redirect: https://github.com/open-telemetry/opentelemetry-proto/blob/main/docs/design-goals.md 301!
+manualLinkTarget: _blank
 --->
 
 # Design Goals for OpenTelemetry Wire Protocol

specification/protocol/requirements.md

@@ -1,5 +1,7 @@
 <!--- Hugo front matter used to generate the website version of this page:
 linkTitle: Requirements
+redirect: https://github.com/open-telemetry/opentelemetry-proto/blob/main/docs/requirements.md 301!
+manualLinkTarget: _blank
 --->
 
 # OpenTelemetry Protocol Requirements