Add yet-another-react-lightbox package and update .gitignore to exclude node_modules

frontend/node_modules/yallist/iterator.js

@@ -1,8 +0,0 @@
-'use strict'
-module.exports = function (Yallist) {
-  Yallist.prototype[Symbol.iterator] = function* () {
-    for (let walker = this.head; walker; walker = walker.next) {
-      yield walker.value
-    }
-  }
-}