ktl-695 chore: support Dokka HTML customization

Author: nikpachoo

build.gradle

@@ -355,3 +355,7 @@ allprojects { subProject ->
                 }
             }
 }
+
+tasks.named("dokkaHtmlMultiModule") {
+    pluginsMapConfiguration.set(["org.jetbrains.dokka.base.DokkaBase": """{ "templatesDir": "$projectDir/dokka-templates" }"""])
+}

dokka-templates/README.md

@@ -0,0 +1,4 @@
+# Customize Dokka's HTML. 
+To customize Dokka's HTML output, place a file in this folder.
+Dokka will find a template file there. If the file is not found, a default one will be used.
+This folder is defined by the templatesDir property.

gradle/dokka.gradle.kts

@@ -27,6 +27,8 @@ tasks.withType(DokkaTaskPartial::class).configureEach {
 
 tasks.withType(DokkaTaskPartial::class).configureEach {
     suppressInheritedMembers.set(true)
+    pluginsMapConfiguration.set(mapOf("org.jetbrains.dokka.base.DokkaBase" to """{ "templatesDir" : "${rootProject.projectDir.resolve("dokka-templates")}" }"""))
+
     dokkaSourceSets.configureEach {
         jdkVersion.set(11)
         includes.from("README.md")