Add vue.js to skills list.

_data/skills.yaml

@@ -93,6 +93,10 @@ categories:
     proficiency: 4
     name: React
     img: skills/libraries/react.svg
+  - id: vue
+    proficiency: 0
+    name: Vue.js
+    img: skills/libraries/vue.png
   - id: jquery
     proficiency: 2
     name: JQuery

_includes/components/footer.njk

@@ -31,6 +31,7 @@
 
   <p>React logo from <a href="https://reactjs.org/">the official site</a>.</p>
   <p>Angular logo from <a href="https://angular.io/presskit">the press kit</a>.</p>
+  <p>Vue.js logo from <a href="https://vuejs.org/">the official site</a>.</p>
   <p>Rails logo from <a href="https://weblog.rubyonrails.org/2016/1/19/new-rails-identity/">the blog</a>.</p>
   <p>Node logo from <a href="https://nodejs.org/en/about/resources/">the logo page</a>.</p>
   <p>Electron logo from <a href="https://commons.wikimedia.org/wiki/File:Electron_Software_Framework_Logo.svg">the Wikimedia logo of the official logo</a>.</p>