Looking at the options for regular text fields I noticed there’s a spellcheck option. This option is missing from the options for textarea fields, though.
In my opinion, a spell checker would be even more useful in textarea fields. Is there something I’m missing? Should I create an issue?
EDIT: I guess it’s rather a docs issue as the textarea field definitely has this option. The markdown plugin surprisingly does not. Maybe because of the docs? 
I don’t find this option in the textarea field implementation, I think it’s missing.
/config/fields/text.php has it, /config/fields/textarea.php doesn’t.
Somehow it still adds the spellcheck="true" attribute, though.
You mean by default or if you set the spellcheck option?
It adds it by default, but I can also set spellcheck: false to get spellcheck="false".
There has to be a configuration somewhere.
Yep, looks like it, but I don’t know where this happens. Since it’s not defined in the textarea props, that’s probably the reason why it doesn’t show up in the auto-generated docs.