Question: why not try to use markdown code blocks? 

Just surround your code in triple backticks: ` character.


Like this
```
here 
<foo>
is <some> </fooer> </foo>
```

An this is the actual raw markdown of my post: https://meta.discourse.org/raw/187974/3

---

You will have to educate your users, but this is your job as a moderator, plus it will help every user who has to deal with markdown later down the line.

You could do this by adding a new global pinned topic, something like "How to embed code on this site" or "How to type on this site".

You can also direct them to this link: [Markdown Reference (commonmark.org)](https://commonmark.org/help/)