Add TypeScript support, fixes #2376

.eslintrc.json

package-lock.json

package.json

resources/assets/javascripts/bootstrap/application.js

resources/assets/javascripts/bootstrap/multi_select.js

resources/assets/javascripts/chunks/vue.js

resources/assets/javascripts/init.js

resources/assets/javascripts/lib/calendar.js

resources/assets/javascripts/lib/event-bus.d.ts

resources/assets/javascripts/lib/event-bus.ts

resources/assets/javascripts/lib/forum.js

resources/assets/javascripts/lib/gettext.js

resources/assets/javascripts/lib/url_helper.d.ts

resources/assets/javascripts/lib/url_helper.ts

resources/assets/javascripts/studip-ui.js

resources/studip.d.ts

resources/vue-shims.d.ts

resources/vue/components/StudipIcon.vue

resources/vue/components/responsive/NavigationItem.vue

tsconfig.json