Re-add syntax highlighting to daily emails and

...ATDC lessons

source/_daily_emails/2022-10-09.md

@@ -37,7 +37,7 @@ It also makes it more obvious to anyone reading the code that these values are b
 
 It's similar to having this example PHP code:
 
-```php
+```language-php
 function __invoke(string $type, int $limit): void {};
 ```