add usage example to readme

README.md

@@ -1,3 +1,41 @@
 # Markdown to HTML Page Generator Gradle Plugin
 This Gradle plugin's goal is to provide a way of using [the maven markdown-page-generator-plugin
  by walokra](https://github.com/walokra/markdown-page-generator-plugin).
+
+Usage example (Kotlin DSL):
+```kotlin
+buildscript {
+    dependencies {
+        classpath("com.github.monosoul:markdown-page-generator-gradle-plugin:2.1.0")
+    }
+
+    repositories {
+        jcenter()
+    }
+}
+
+apply(plugin = "com.github.monosoul.markdown.page.generator")
+
+tasks {
+
+    val generateHtml = getByName("generateHtml", GenerateHtmlTask::class) {
+        dependsOn(processResources)
+
+        val encoding = "UTF-8"
+
+        recursiveInput = true
+        pegdownExtensions = "TABLES,FENCED_CODE_BLOCKS"
+        inputEncoding = encoding
+        outputEncoding = encoding
+
+        val sourceDir = File(buildDir, "resources/main/markdown")
+        val outputDir by extra { File(buildDir, "html") }
+
+        inputDirectory = sourceDir
+        outputDirectory = outputDir
+        headerHtmlFile = File(sourceDir, "header.html")
+        footerHtmlFile = File(sourceDir, "footer.html")
+        transformRelativeMarkdownLinks = true
+    }
+}
+```