PLT-1236 Added special handling for markdown links within mattermost (#2763)

* Added special handling for markdown links within mattermost

* Moved application of .app__body class to route components

webapp/components/tutorial/tutorial_view.jsx

@@ -6,6 +6,7 @@ import TutorialIntroScreens from './tutorial_intro_screens.jsx';
 import ChannelStore from 'stores/channel_store.jsx';
 import Constants from 'utils/constants.jsx';
 
+import $ from 'jquery';
 import React from 'react';
 
 export default class TutorialView extends React.Component {
@@ -20,9 +21,13 @@ export default class TutorialView extends React.Component {
     }
     componentDidMount() {
         ChannelStore.addChangeListener(this.handleChannelChange);
+
+        $('body').addClass('app__body');
     }
     componentWillUnmount() {
         ChannelStore.removeChangeListener(this.handleChannelChange);
+
+        $('body').removeClass('app__body');
     }
     handleChannelChange() {
         this.setState({