code: public void removeListIndent(final Configuration configuration)
      {
          Line line = this.lines;
          while (line != null)
          {
              if (!line.isEmpty)
              {
                  switch (line.getLineType(configuration))
                  {
                  case ULIST:
                      line.value = line.value.substring(line.leading + 2);
                      break;
                  case OLIST:
                      line.value = line.value.substring(line.value.indexOf('.') + 2);
                      break;
                  default:
                      line.value = line.value.substring(Math.min(line.leading, 4));
                      break;
                  }
                  line.initLeading();
              }
              line = line.next;
          }
      }
docs: Used for nested lists. Removes list markers and up to 4 leading spaces.
  
  @param configuration
  txtmark configuration