Simple "Add to Homescreen" manifest (PWA) (#411)

* simple "add to homescreen" manifest

* remove ?source=pwa

Co-authored-by: Adam Stachowicz <saibamenppl@gmail.com>

* run TinyPNG

Co-authored-by: Adam Stachowicz <saibamenppl@gmail.com>
Co-authored-by: LouisLam <louislam@users.noreply.github.com>

public/manifest.json

@@ -0,0 +1,19 @@
+{
+    "name": "Uptime Kuma",
+    "short_name": "Uptime Kuma",
+    "start_url": "/",
+    "background_color": "#fff",
+    "display": "standalone",
+    "icons": [
+        {
+            "src": "icon-192x192.png",
+            "sizes": "192x192",
+            "type": "image/png"
+        },
+        {
+            "src": "icon-512x512.png",
+            "sizes": "512x512",
+            "type": "image/png"
+        }
+    ]
+}