code: public EmbedBuilder appendDescription(CharSequence description)
      {
          Checks.notNull(description, "description");
          Checks.check(this.description.length() + description.length() <= MessageEmbed.TEXT_MAX_LENGTH,
                  "Description cannot be longer than %d characters.", MessageEmbed.TEXT_MAX_LENGTH);
          this.description.append(description);
          return this;
      }
docs: Appends to the description of the embed. This is where the main chunk of text for an embed is typically placed.
  
  <p><b><a href="http://i.imgur.com/lbchtwk.png">Example</a></b>
  
  @param  description
  the string to append to the description of the embed
  
  @throws java.lang.IllegalArgumentException
  <ul>
  <li>If the provided {@code description} String is null</li>
  <li>If the length of {@code description} is greater than {@link net.dv8tion.jda.core.entities.MessageEmbed#TEXT_MAX_LENGTH}.</li>
  </ul>
  
  @return the builder after the description has been set