chore: Fix Git "h" ub typo in all pages

Author: potato4d

src/.vuepress/config/themeConfig.js

@@ -38,7 +38,7 @@ module.exports = {
       link: 'https://twitter.com/vue_a11y'
     },
     {
-      name: 'Github',
+      name: 'GitHub',
       icon: 'github',
       link: 'https://github.com/vue-a11y'
     }

src/.vuepress/theme/components/TheNavigation.vue

@@ -28,7 +28,7 @@
         <ExternalLink
           class="flex items-center px-3 border-b-4 border-transparent border-solid the-nav-link hover:border-accent-primary"
           :href="`https://github.com/vue-a11y`"
-          label="Github"
+          label="GitHub"
         />
       </li>
     </ul>

src/.vuepress/theme/views/Home.vue

@@ -20,7 +20,7 @@
             <ExternalLink
               class="ml-4 text-lg md:text-xl btn btn-light"
               :href="`https://github.com/${$themeConfig.repo}`"
-              label="Github"
+              label="GitHub"
             />
           </div>
         </div>