new mimes

[eluser]Unknown[/eluser]
hi,
I'am new in the forum , but will contribute with the mimes.php,

'docx' => 'application/vnd.openxmlformats-officedocument.wordprocessingml.document', 'xlsx' => 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
'pptx' => 'application/vnd.openxmlformats-officedocument.presentationml.presentation',
'xlsx' => 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',