Re-add syntax highlighting to daily emails and

...ATDC lessons

source/_daily_emails/2023-04-12.md

@@ -14,7 +14,7 @@ If I'm passing arguments into a constructor, I can declare a visibility and it w
 
 Here's an example of a value of a data transfer object that accepts a sort code and account number as strings:
 
-```php
+```language-php
 class AccountDetails {
 
   public function __construct(
@@ -27,7 +27,7 @@ class AccountDetails {
 
 Without promoted constructor properties, I'd need to create the properties and assign them manually, and I'd have this:
 
-```php
+```language-php
 class AccountDetails {
 
   public string $accountNumber;