Updated homepage video to Vue 3 version (#485)

Author: atomjar

src/.vuepress/components/common/vuemastery-video-modal.vue

@@ -3,7 +3,7 @@
     <div ref="modal" class="modal" :class="{ open: isOpen }">
       <div class="video-space" style="padding: 56.25% 0 0 0; position: relative;">
         <iframe
-          src="https://player.vimeo.com/video/247494684?dnt=1"
+          src="https://player.vimeo.com/video/455611549?dnt=1"
           style="height: 100%; left: 0; position: absolute; top: 0; width: 100%; margin: 0"
           frameborder="0"
           webkitallowfullscreen
@@ -23,7 +23,7 @@
         >Vue Mastery</a>.
         Watch Vue Mastery’s free
         <a
-          href="https://www.vuemastery.com/courses/intro-to-vue-js/vue-instance/"
+          href="https://www.vuemastery.com/courses/intro-to-vue-3/intro-to-vue3"
           target="_blank"
           rel="sponsored noopener"
           title="Vue.js Courses on Vue Mastery"