(feat): whitehouse email template

Core/Email/Campaigns/Templates/whitehouse.md.tpl

+Breaking news. [Bill Ottman](https://www.minds.com/ottman?__e_ct_guid=<?= $vars['guid']?>&campaign=<?= $vars['campaign']?>&topic=<?= $vars['topic'] ?>&validator=<?= $vars['validator']?>), CEO and co-founder of Minds, is attending The White House Social Media Summit to discuss transparency, privacy, digital rights and civil discourse between the left and right both online and offline. 
+
+Use hashtag [#minds](https://www.minds.com/newsfeed/global/top;period=24h;hashtag=minds) everywhere! 
+
+Happy July
+
+| |
+|:--:|
+| [![The White House Invitation](https://cdn-assets.minds.com/emails/whitehouse.jpg){=600x}](https://www.minds.com/newsfeed/global/top;period=24h;hashtag=minds?__e_ct_guid=<?= $vars['guid']?>&campaign=<?= $vars['campaign']?>&topic=<?= $vars['topic'] ?>&validator=<?= $vars['validator']?>)
+| |
+