GH-256 - Added Kotlin variant for Java code.

Author: Devashish Bhattacharjee

src/docs/antora/modules/ROOT/pages/documentation.adoc

@@ -13,7 +13,11 @@ Spring Modulith's `Documenter` abstraction can produce two different kinds of sn
 The documentation snippets can be generated by handing the `ApplicationModules` instance into a `Documenter`.
 
 .Generating application module component diagrams using `Documenter`
-[source, java]
+[tabs]
+======
+Java::
++
+[source, java, role="primary"]
 ----
 class DocumentationTests {
 
@@ -28,6 +32,22 @@ class DocumentationTests {
   }
 }
 ----
+Kotlin::
++
+[source, kotlin, role="secondary"]
+----
+class DocumentationTests {
+    private val modules = ApplicationModules.of(Application::class)
+
+    @Test
+    fun writeDocumentationSnippets() {
+        Documenter(modules)
+            .writeModulesAsPlantUml()
+            .writeIndividualModulesAsPlantUml()
+    }
+}
+----
+======
 
 The first call on `Documenter` will generate a C4 component diagram containing all modules within the system.
 
@@ -90,13 +110,23 @@ SHOW_LEGEND()
 === Using Traditional UML Component Diagrams
 
 If you prefer the traditional UML style component diagrams, tweak the `DiagramOptions` to rather use that style as follows:
-
-[source, java]
+[tabs]
+======
+Java::
++
+[source, java, role="primary"]
 ----
 DiagramOptions.defaults()
   .withStyle(DiagramStyle.UML);
 ----
-
+Kotlin::
++
+[source, kotlin, role="secondary"]
+----
+DiagramOptions.defaults()
+  .withStyle(DiagramStyle.UML)
+----
+======
 This will cause the diagrams to look like this:
 
 .All modules and their relationships rendered as UML component diagram
@@ -184,7 +214,11 @@ package "Application" <<Container>> {
 The Application Module Canvases can be generated by calling `Documenter.writeModuleCanvases()`:
 
 .Generating application module canvases using `Documenter`
-[source, java]
+[tabs]
+======
+Java::
++
+[source, java, role="primary"]
 ----
 class DocumentationTests {
 
@@ -198,7 +232,22 @@ class DocumentationTests {
   }
 }
 ----
+Kotlin::
++
+[source, kotlin, role="secondary"]
+----
+class DocumentationTests {
+
+  private val modules = ApplicationModules.of(Application::class)
 
+  @Test
+  fun writeDocumentationSnippets() {
+    Documenter(modules)
+        .writeModuleCanvases()
+  }
+}
+----
+======
 By default, the documentation will be generated to `spring-modulith-docs` folder in your build system's build folder.
 A generated canvas looks like this: