Standard Markdown syntax applies. [![alt](img-to-display)]](link-to-higher-rez)
Goldmark follows the Commonmark spec, so it’s not requirining anything special.
Also no way to enter inline styles through Markdown syntax, however these are strongly discouraged in this day and age. Also the align attribute is not supported by HTML5.
For outputting more complex HTML markup have a look at: Shortcodes | Hugo