docs: fix broken links (#2885)

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docs/source/entities.mdx

@@ -85,7 +85,7 @@ type Product @key(fields: "id") {
 
 Though not strictly required, it's best to use non-nullable fields for keys. If you use fields that return `null` values, GraphOS may encounter issues resolving the entity.
 
-For more information on advanced key options, like how to define [multiple keys](./entities-advanced/#multiple-keys) or [compound keys](/entities-advanced/#compound-keys), see [Advanced topics for federation entities](./entities-advanced).
+For more information on advanced key options, like how to define [multiple keys](./entities-advanced/#multiple-keys) or [compound keys](./entities-advanced/#compound-keys), see [Advanced topics for federation entities](./entities-advanced).
 
 ### 2. Define a reference resolver
 

docs/source/managed-federation/deployment.mdx

@@ -167,7 +167,7 @@ As an example, follow these steps to deploy with a supergraph schema of a new re
     }
     ```
 
-  This initiates a [launch](/graphos/delivery/launches/), as well as any downstream launches necessary for [contracts](graphos/delivery/contracts/#automatic-updates). It returns the launch IDs, with downstream launch IDs configured to return synchronously (`downstreamLaunchInitiation: "SYNC"`) with the mutation.
+  This initiates a [launch](/graphos/delivery/launches/), as well as any downstream launches necessary for [contracts](/graphos/delivery/contracts/#automatic-updates). It returns the launch IDs, with downstream launch IDs configured to return synchronously (`downstreamLaunchInitiation: "SYNC"`) with the mutation.
 
   <Note>
 

docs/source/metrics.md

@@ -35,7 +35,7 @@ If your library _does_ support federated tracing, see its documentation to learn
 
 ### In the Apollo Router
 
-See [Sending Apollo Router usage data to GraphOS](/router/configuration/apollo-telemetry).
+See [Sending Apollo Router usage data to GraphOS](/router/configuration/telemetry/apollo-telemetry).
 
 ### In `@apollo/gateway`