Format API tutorial/documentation

Hi,

I would like to transition toward Gutenberg (rather than htlm + short codes), but I need to adapt my tools, including inline formatting and more advance tools (e.g. for giving sources). I need to be able to add parameters I can easily control, like those of the current “link” (Ctrl+K) format—which, by the way, I also need to complete.
For that, I understand that I shall use the Format API, but the only documentation I could find is largely insufficient. I found a post about a tutorial, but said tutorial seems to have disappeared.

By the way, since I have to extend the ‘link’ format, the ‘image’ block, etc… Is there a way to modify or replace them so I don’t keep unfitted propositions in my menus?

Thank you.