add some comment to config

Author: streamtw

src/config/lfm.php

@@ -66,7 +66,7 @@
         'file'  => [
             'folder_name'  => 'files',
             'startup_view' => 'grid',
-            'max_size'     => 50000,
+            'max_size'     => 50000, // size in KB
             'valid_mime'   => [
                 'image/jpeg',
                 'image/pjpeg',
@@ -78,7 +78,7 @@
         'image' => [
             'folder_name'  => 'photos',
             'startup_view' => 'list',
-            'max_size'     => 50000,
+            'max_size'     => 50000, // size in KB
             'valid_mime'   => [
                 'image/jpeg',
                 'image/pjpeg',