task.getInputEncoding().convention(Charset.defaultCharset().name());
            task.getOutputEncoding().convention(Charset.defaultCharset().name());

            task.getMarkdownFile().convention(extension.getReleaseNotes().getMarkdownFile());
            task.getDestinationFile().convention(extension.getStagingRoot().file("release-notes/raw.html"));
        });

@CacheableTask
public abstract class RenderMarkdown extends DefaultTask {
    /**
     * The source markdown file.
     */
    @PathSensitive(PathSensitivity.NONE)
    @InputFile
    public abstract RegularFileProperty getMarkdownFile();

    /**
     * The rendered HTML file
     */
    @OutputFile
    public abstract RegularFileProperty getDestinationFile();

    /**
     * Encoding of input file
     */
    @Input

import org.gradle.api.file.RegularFileProperty;

public abstract class ReleaseNotes {
    /**
     * The source markdown file for the release notes.
     */
    public abstract RegularFileProperty getMarkdownFile();

    /**
     * The base CSS file used by all documentation.
     */
    public abstract RegularFileProperty getBaseCssFile();

    /**
     * The release notes specific CSS file
     */