Fix string delimiters being unstyled in code blocks

[HeySora]

For some reason, single quotation marks are marked as .dl and separate from the actual string (here, .s1); but double quotation marks are part of the same element as the string itself (.s2)

This PR fixes this absolutely minor detail that probably nobody ever noticed :joy:

Fixed:

[maximevaillancourt]

You're on a roll lately. Thank you so much! 😄