code: function writeChangelog(changelog) {
        var fileContents = null;
        var firstLineFile = null;
        var firstLineFileHeader = null;
        var regex = null;
  
        if (options.insertType && grunt.file.exists(options.dest)) {
          fileContents = grunt.file.read(options.dest);
          firstLineFile = fileContents.split('\n')[0];
          grunt.log.debug('firstLineFile = ' + firstLineFile);
  
          switch (options.insertType) {
            case 'prepend':
              changelog = changelog + '\n' + fileContents;
              break;
            case 'append':
              changelog = fileContents + '\n' + changelog;
              break;
            default:
              grunt.fatal('"' + options.insertType + '" is not a valid insertType. Please use "append" or "prepend".');
              return false;
          }
        }
  
        if (options.fileHeader) {
          firstLineFileHeader = options.fileHeader.split('\n')[0];
          grunt.log.debug('firstLineFileHeader = ' + firstLineFileHeader);
  
          if (options.insertType === 'prepend') {
            if (firstLineFile !== firstLineFileHeader) {
              changelog = options.fileHeader + '\n\n' + changelog;
            } else {
              regex = new RegExp(options.fileHeader+'\n\n','m');
              changelog = options.fileHeader + '\n\n' + changelog.replace(regex, '');
            }
  
          // insertType === 'append' || undefined
          } else {
            if (firstLineFile !== firstLineFileHeader) {
              changelog = options.fileHeader + '\n\n' + changelog;
            }
          }
  
        }
  
  
        grunt.file.write(options.dest, changelog);
  
        // Log the results.
        grunt.log.ok(changelog);
        grunt.log.writeln();
        grunt.log.writeln('Changelog created at '+ options.dest.toString().cyan + '.');
      }
docs: Write the changelog to the destination file.