Escaped double quotes inside double quotes

When having something like:
~~~
Title aa

"Pre\"B\"Post"

```
  "G"
```
~~~
we get the warning:
```
aa.md:7: warning: unexpected command endcode
```

this looks like to be introduced in version 1.9.2 and a regression regarding:
```
Commit: 2683d17 [2683d17]
Date: Friday, April 30, 2021 12:26:12 PM
issue #8525 Links aren't properly rendered when preceded by quoted text

2 or more returns inside a quoted text were not handled properly, added a repeat count.
```
Note that the output originally was not ok either (missing some backslashes).
Note checked #8525 again as well, looks OK.

src/doctokenizer.l

@@ -318,7 +318,7 @@ LNKWORD3  ([0-9a-z_A-Z\-]+("/"|"\\"))*[0-9a-z_A-Z\-]+("."[0-9a-z_A-Z]+)+
 CHARWORDQ [^ \t\n\r\\@<>()\[\]:;\?{}&%$#,."=']
 ESCWORD   ("%"{ID}(("::"|"."){ID})*)|("%'")
 CHARWORDQ1 [^ \-+0-9\t\n\r\\@<>()\[\]:;\?{}&%$#,."=']
-WORD1     {ESCWORD}|{CHARWORDQ1}{CHARWORDQ}*|"{"|"}"|"'\"'"|("\""([^"\n]*\n?)*[^"\n]*"\"")
+WORD1     {ESCWORD}|{CHARWORDQ1}{CHARWORDQ}*|"{"|"}"|"'\"'"|("\""([^"\n]*(\\\")?\n?)*[^"\n]*"\"")
 WORD2     "."|","|"("|")"|"["|"]"|"::"|":"|";"|"\?"|"="|"'"
 WORD1NQ   {ESCWORD}|{CHARWORDQ}+|"{"|"}"
 WORD2NQ   "."|","|"("|")"|"["|"]"|"::"|":"|";"|"\?"|"="|"'"