Add drawback about dr"..." strings

Co-authored-by: Ed Page <[email protected]>

Author: nik-rev

text/3830-dedented-string-literals.md

@@ -941,6 +941,8 @@ let _ = d"
 # Drawbacks
 [drawbacks]: #drawbacks
 
+- While the reference specifies `r` as ["not processing ay escapes"](https://doc.rust-lang.org/reference/tokens.html#raw-string-literals), users are less likely familiar with the exact definition and more familiar with the name and the affect: it leaves the string as-is.  This can feel contradictory to `d` which is a specific form of modifying the string content and so a `dr""` could read as something that should be a compilation error.
+
 - The more string literal modifiers that are stacked on each other, more work is needed to decipher it and can feel a bit too foreign
 
 - Contributes to the increase of string literal modifiers by adding a new variant.