added favicons and webapp metadata (#211)

public/browserconfig.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<browserconfig>
+    <msapplication>
+        <tile>
+            <square70x70logo src="favicon/mstile-small.jpg"/>
+            <square150x150logo src="favicon/mstile-medium.jpg"/>
+            <wide310x150logo src="favicon/mstile-wide.jpg"/>
+            <square310x310logo src="favicon/mstile-large.jpg"/>
+            <TileColor>#00a300</TileColor>
+        </tile>
+    </msapplication>
+</browserconfig>

public/manifest.json

@@ -0,0 +1,21 @@
+{
+  "name": "Kimai Time-Tracker",
+  "short_name": "Kimai 2",
+  "icons": [
+    {
+      "src": "favicon-32x32.png",
+      "sizes": "32x32",
+      "type": "image/png",
+      "density": "0.75"
+    },
+    {
+      "src": "touch-icon-192x192.png",
+      "sizes": "192x192",
+      "type": "image/png",
+      "density": "4.0"
+    }
+  ],
+  "theme_color": "#ffffff",
+  "background_color": "#ffffff",
+  "display": "standalone"
+}