add offline functionality by making this a PWA

- added favicons
- added manifest
- split javascript into main.js and elevators.js

elevators.js

@@ -6,11 +6,6 @@ let geolocationPermission = false;
 let geolocation = null;
 const openStations = new Set();
 let sortByDistance = false;
-const version = '0.5.2'
-const minorVersion = version.split('.').splice(0, 2).join('.');
-const numberFormat = new Intl.NumberFormat('de-DE', {
-    maximumFractionDigits: 1
-});
 
 const substituteData = [
     {
@@ -87,14 +82,6 @@ const substituteData = [
     },
 ]
 
-
-Object.defineProperty(String.prototype, 'capitalize', {
-    value: function () {
-        return this.charAt(0).toUpperCase() + this.toLowerCase().slice(1);
-    },
-    enumerable: false
-});
-
 async function loadElevators() {
     document.querySelector('#errorMessage').classList.add('hidden');
     const res = await fetch('https://www.hvv.de/elevators', {
@@ -203,12 +190,6 @@ async function loadElevators() {
     }));
 }
 
-const dateTimeStyle = new Intl.DateTimeFormat('de-DE', {
-    dateStyle: 'medium',
-    timeStyle: 'medium',
-    timeZone: 'Europe/Berlin',
-})
-
 async function loadOsmData() {
     const nodeIdList = [];
     for (const station of internalData.stations) {
@@ -726,21 +707,6 @@ document.querySelectorAll('button.typeChip').forEach(e => {
     })
 })
 
-function openDialog(selector) {
-    document.querySelector('body').classList.add('has-dialog')
-    document.querySelector('#dialog_layer').classList.add('active')
-    document.querySelector(selector).classList.remove('hidden')
-}
-
-function closeDialog(selector) {
-    document.querySelector('body').classList.remove('has-dialog')
-    document.querySelector('#dialog_layer').classList.remove('active')
-    document.querySelector(selector).classList.add('hidden')
-}
-
-// set version
-document.querySelector('#version').innerHTML = `v${version}`;
-
 // data api version check
 const check_internal = JSON.parse(localStorage.getItem("internal_data"));
 const check_osm = JSON.parse(localStorage.getItem("osm_data"));