Add external link indicators to API docs in Antora

Closes gh-40817

spring-boot-project/spring-boot-docs/src/docs/antora/antora.yml

@@ -9,24 +9,3 @@ ext:
       classifier: catalog-content
       module: api
       destination: content-catalog
-  nav-attributes:
-  - path: "Overview"
-    attributes: { icon: home }
-  - path: "Documentation"
-    attributes: { icon: book }
-  - path: "Community"
-    attributes: { icon: question }
-  - path: "System Requirements"
-    attributes: { icon: server }
-  - path: "Installing Spring Boot"
-    attributes: { icon: gift }
-  - path: "Upgrading Spring Boot"
-    attributes: { icon: rocket }
-  - path: [ "Java APIs", "Spring Boot" ]
-    attributes: { external: true }
-  - path: [ "Java APIs", "Maven Plugin" ]
-    attributes: { external: true}
-  - path: [ "Java APIs", "Gradle Plugin" ]
-    attributes: { external: true }
-  - path: [ "Kotlin APIs", "Spring Boot" ]
-    attributes: { external: true }

spring-boot-project/spring-boot-docs/src/docs/antora/modules/ROOT/partials/nav-root.adoc

@@ -1,6 +1,6 @@
-* xref:index.adoc[]
-* xref:documentation.adoc[]
-* xref:community.adoc[]
-* xref:system-requirements.adoc[]
-* xref:installing.adoc[]
-* xref:upgrading.adoc[]
+* xref:index.adoc[,role=navtree-icon-home]
+* xref:documentation.adoc[,role=navtree-icon-book]
+* xref:community.adoc[,role=navtree-icon-question]
+* xref:system-requirements.adoc[,role=navtree-icon-server]
+* xref:installing.adoc[,role=navtree-icon-gift]
+* xref:upgrading.adoc[,role=navtree-icon-rocket]

spring-boot-project/spring-boot-docs/src/docs/antora/modules/api/partials/nav-java-api.adoc

@@ -1,4 +1,4 @@
 * Java APIs
-** xref:api:java/index.html[Spring Boot]
-** xref:gradle-plugin:api/java/index.html[Gradle Plugin]
-** xref:maven-plugin:api/java/index.html[Maven Plugin]
+** xref:api:java/index.html[Spring Boot,role=link-external, window=_blank]
+** xref:gradle-plugin:api/java/index.html[Gradle Plugin,role=link-external, window=_blank]
+** xref:maven-plugin:api/java/index.html[Maven Plugin,role=link-external, window=_blank]

spring-boot-project/spring-boot-docs/src/docs/antora/modules/api/partials/nav-kotlin-api.adoc

@@ -1,2 +1,2 @@
 * Kotlin APIs
-** xref:api:kotlin/index.html[Spring Boot]
+** xref:api:kotlin/index.html[Spring Boot,role=link-external, window=_blank]