get the quote characters right in the readme

README.md

@@ -708,7 +708,7 @@ filters on the key values is performed.
   '\`' can also be used as a literal string notation, and it also allows binary
   string notation see
   [binary strings](https://cliutils.github.io/CLI11/book/chapters/config.html).
-  The escaped string processing will remove outer quotes if present, '"' will
+  The escaped string processing will remove outer quotes if present, `"` will
   indicate a string with potential escape sequences, `'` and '\`' will indicate
   a literal string and the quotes removed but no escape sequences will be
   processed. This is the same escape processing as used in config files.