{
 "name": "Guilherme/guitheme",
 "description": "guitheme",
 "require": {
   "php": "~5.5.0|~5.6.0|~7.0.0",
   "magento/theme-frontend-blank": "100.0.*",
   "magento/framework": "100.0.*"
 },
 "type": "magento2-theme",
 "version": "1.0.0",
 "license": ["OSL-3.0","AFL-3.0" ],
 "autoload": {
   "files": [
     "registration.php"]} }

<image id="category_page_grid" type="small_image"><width>240</width<height>300</height></image>

<?php
   MagentoFrameworkComponentComponentRegistrar::register(
   MagentoFrameworkComponentComponentRegistrar::THEME,
   'frontend/Guilherme/guitheme',
   __DIR__
   );
   ?>

<theme xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Config/etc/theme.xsd">
        <title>guitheme</title>
        <parent>Magento/blank</parent>
        <media>
            <preview_image>media/logoimage.jpg</preview_image>
        </media>
</theme>