Docsify and some Markdown viewers supports mixing HTML and Markdown elements in the same document. There must be a blank line between the two formats.
<center>

</center>
Note the blank line between the <center> HTML tag and the  Markdown tag.
Multi column layouts can be created using HTML div tags with following CSS classes:
grid2,grid3,grid4: Define a section with 2, 3 or 4 columnscol: Define a column inside of a grid section
Here is an example of a 3 column layout
<div class="grid3"><div class="col">
<center>
**Column 1**
</center>
1. one
2. two
3. three
</div><div class="col">
<center>
**Column 2**
</center>
* one
* two
* three
</div><div class="col">
<center>
**Column 3**
</center>
>blaa blaa blaa
</div></div>