chore: fix syntax highlighting languages

src/content/daily-email/2023-04-15.md

@@ -13,7 +13,7 @@ Instead of doing this manually, I can achieve the same thing though using a tool
 
 Here's an example where I'm automatically re-running my PHPUnit tests using a `just test` recipe each time a file within my custom modules directory changes:
 
-```plain
+```
 nodemon \
   --watch web/modules/custom \
   --ext '*' \