[8.4](backport #3476) [apm docs consolidation] Clean up

docs/en/apm-server/api-error.asciidoc

@@ -12,5 +12,5 @@ APM Server uses JSON Schema to validate requests. The specification for errors i
 
 [source,json]
 ----
-include::./spec/v2/error.json[]
+include::{apm-server-root}/docs/spec/v2/error.json[]
 ----

docs/en/apm-server/api-event-example.asciidoc

@@ -5,5 +5,5 @@ A request body example containing one event for all currently supported event ty
 
 [source,json]
 ----
-include::./data/intake-api/generated/events.ndjson[]
+include::{apm-server-root}/docs/data/intake-api/generated/events.ndjson[]
 ----

docs/en/apm-server/api-metadata.asciidoc

@@ -62,5 +62,5 @@ APM Server uses JSON Schema to validate requests. The specification for metadata
 
 [source,json]
 ----
-include::./spec/v2/metadata.json[]
+include::{apm-server-root}/docs/spec/v2/metadata.json[]
 ----

docs/en/apm-server/api-metricset.asciidoc

@@ -12,5 +12,5 @@ APM Server uses JSON Schema to validate requests. The specification for metrics
 
 [source,json]
 ----
-include::./spec/v2/metricset.json[]
+include::{apm-server-root}/docs/spec/v2/metricset.json[]
 ----

docs/en/apm-server/api-span.asciidoc

@@ -12,5 +12,5 @@ APM Server uses JSON Schema to validate requests. The specification for spans is
 
 [source,json]
 ----
-include::./spec/v2/span.json[]
+include::{apm-server-root}/docs/spec/v2/span.json[]
 ----

docs/en/apm-server/api-transaction.asciidoc

@@ -12,5 +12,5 @@ APM Server uses JSON Schema to validate requests. The specification for transact
 
 [source,json]
 ----
-include::./spec/v2/transaction.json[]
+include::{apm-server-root}/docs/spec/v2/transaction.json[]
 ----

docs/en/apm-server/data-model.asciidoc

@@ -88,7 +88,7 @@ This example shows what span documents can look like when indexed in {es}.
 ====
 [source,json]
 ----
-include::./data/elasticsearch/generated/spans.json[]
+include::{apm-server-root}/docs/data/elasticsearch/generated/spans.json[]
 ----
 ====
 
@@ -159,7 +159,7 @@ This example shows what transaction documents can look like when indexed in {es}
 ====
 [source,json]
 ----
-include::./data/elasticsearch/generated/transactions.json[]
+include::{apm-server-root}/docs/data/elasticsearch/generated/transactions.json[]
 ----
 ====
 
@@ -212,7 +212,7 @@ This example shows what error documents can look like when indexed in {es}.
 ====
 [source,json]
 ----
-include::./data/elasticsearch/generated/errors.json[]
+include::{apm-server-root}/docs/data/elasticsearch/generated/errors.json[]
 ----
 ====
 
@@ -388,7 +388,7 @@ These fields make it possible to search and aggregate across various dimensions,
 
 [source,json]
 ----
-include::./data/elasticsearch/metricset.json[]
+include::{apm-server-root}/docs/data/elasticsearch/metricset.json[]
 ----
 ====