add version information to index page

lib/index.js

@@ -53,7 +53,7 @@ if (certEndpoint) {
 }
 
 app.get('/', (req, res) => {
-  res.render('index')
+  res.render('index', { version })
 })
 
 app.get('/error', (req, res) => {

lib/views/index.ejs

@@ -75,6 +75,7 @@
     </article>
 
     <footer>
+      v.<%= version %> ◆
       Created by <a href="https://ondrejsynacek.com" target="_blank">Ondrej Synacek</a> (2019) ◆
       <a href="https://github.com/comatory/fb2iCal" target="_blank" title="Github">Source</a> ◆
       <a href="/about" target="_blank" title="About the project">About</about>