Add comment in maven example

[yoghurt1131]

In. Setting up for JVM documentation, I'd like to add a comment in maven example like gradle one. ( I guess kotlin-reflect is often used in compile scope. )

+   <!-- spek requires kotlin-reflect, can be omitted if already in the classpath -->
    <dependency>
        <groupId>org.jetbrains.kotlin</groupId>
        <artifactId>kotlin-reflect</artifactId>
        <version>${kotlin.version}</version>
        <scope>test</scope>
    </dependency>
</dependencies>
...