Add empty headers to HTML tables without headers when converted to markdown

[NikolasKomonen]

This is necessary because Markdown will not render a table without a header defined.

Related issue here: giflw#9

Here is an example of the markdown not rendering without the empty table header.

[kotcrab]

Looks okay. Can you format the source code so it matches original files?
Also you can undo the changes on MultiMarkdownTest.java, only the formatting was changed. Generally we want to avoid changes like this because it adds unnecessary noise to git history.

[NikolasKomonen]

@kotcrab Sorry I forgot to revert the MultiMarkdownTest changes. Everything should be fixed up. Let me know if there's anything else that needs a change.

[kotcrab]

Alright, I see what's wrong. The indentation on your changes is off. This project is unfortunate enough to be using tabs and your changes are using spaces. It may look fine on your end but on Github it's clearly different, you can see it after going to "Files changed" tab.

[NikolasKomonen]

@kotcrab Yup, found the indentation issues. Everything should be good now.

[kotcrab]

Looks good now, thanks! I'm going to upload v1.1.0 soon.

[NikolasKomonen]

@kotcrab Great to see the change up on the maven repo. Thanks a lot for the help!