As I went and formatted the first chapter, I found pretty fast, how to center text and images. Knowing a bit of HTML, that is no rocket-science, knowing that you can mix both HTML and Markdown though ... is easily forgotten.
Putting all that aside, I continued on, noticing that ... the rest of the text is centered as well. Going by HTML logic, it shouldn't be centered. I even tried out the markdown editor on the main steemit blog platform. My guess is, that the mixed Markdown/HTML-Interpreter of Steemit has a bug at the moment.
How to solve that problem then? As you clearly see, the Text doesn't appear centered. The workaround lies in Steemit's Advanced Formatting Functions:
<div class="text-justify">
Chapter-Text
</div>
This allowed me to re-align the text to the left. But instead of a ragged alignment, this results in a justified text. I didn't want to start using any of the other methods, as they are more suited to having a picture float left or right from the text. It is not quite what I wanted, especially since ragged alignment is more suited to online publication, as most browsers can't do automated hyphenation, which is normally needed to avoid huge spaces between words. It still looks better than centered text though ...