HTML blocks not support

[sunshineormer]

This plugin you made is useful ,Thank U.
Now ,I have a little issue with this plugin . Once I wrote a html block in the MD section，just like

## title1 
<div _class:ldiv>
 some bla bla ...
</div>

VSCode and OB works well ,but the preview of this plugin doesn't work . It maybe a little problem of usage with markdown-it .
The support of HTML blocks is very useful and expected 。

thanks again.