I’d like to support this request. Even when not in a coding editor I so often need to put parenthesis around parts of sentences - i fsimply to make them stand out or assign some retrievable keywords or whatever - sort of »content markers«.
After all Agendea is also working as a sort of an information bank. Although you surely can use it to write up write Articles and essays - but then most like you woud do this in a more dedicated editor. But even then collecting the bits and pieces within Agenda requires structure and content markers .
Yes. That would be so nice 
. And it goes for all those ([{ but also for the Quotation markers basically all the major paired keys.