Processor second pass in enum refactor demo

Processor.java

public class Processor {
  public void processFile(Path file) {
    switch (DocumentType.forPath(file)) {
    case TXT:
      processTextFile(file);
      break;
    case MD:
      processMarkdownFile(file);
      break;
    case HTML:
      processHtmlFile(file);
      break;
    }
  }
  // ... the rest is as before ...
}