Backquotes around model_type

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: morsssss

docs/learning-how-tos/examples-and-guides/translation-beginners-guide.mdx

@@ -840,7 +840,7 @@ Congratulations! Now you know how to send the DeepL API a translation request in
 | source language | `source_lang` | optional |
 | target language | `target_lang` | required |
 | text to translate | `text` | required |
-| optimize for speed or quality | model_type | optional |
+| optimize for speed or quality | `model_type` | optional |
 
 Here are some possible next steps: