Markdown: Fix dinkus formatter with codefences

Change how the formatter is applied to use an invisible null unicode
character instead of div tags and add a newline to preserve the DOM
tree so codeblocks and child elements aren't altered.

Signed-off-by: kingbri <bdashore3@proton.me>

public/scripts/showdown-dinkus.js

@@ -20,6 +20,6 @@ export const dinkusExtension = () => {
     return [{
         type: "lang",
         regex: replaceRegex,
-        replace: (match) => match.replace(replaceRegex, `<div>${savedDinkus}</div>`).trim()
+        replace: (match) => match.replace(replaceRegex, `\u0000${savedDinkus} \n`)
     }];
 }