feat: email abstract

src/Mailer.php

@@ -42,7 +42,7 @@ class Mailer {
         foreach ( $dirs as $dir ) {
             $resolver->appendResolver( new DirResolver( $dir ) );
         }
-        $resolver->appendResolver( new DirResolver( __DIR__ . '/templates' ) );
+        $resolver->appendResolver( new DirResolver( dirname( __DIR__, 2 ) . '/templates' ) );
 
         return new SimplePhpRenderer( $resolver );
     }