fix server worker is blocked (#565)

* fix server worker is blocked

* Also use relURL in manifest

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Co-authored-by: Alex Shpak <alex-shpak@users.noreply.github.com>

assets/manifest.json

 {
   "name": "{{ .Site.Title }}",
   "short_name": "{{ .Site.Title }}",
-  "start_url": "{{ "/" | relURL }}",
-  "scope": "{{ "/" | relURL }}",
+  "start_url": "{{ "./" | relURL }}",
+  "scope": "{{ "./" | relURL }}",
   "display": "standalone",
   "background_color": "#000000",
   "theme_color": "#000000",
   "icons": [
     {
-      "src": "{{ "/favicon.svg" | relURL }}",
+      "src": "{{ "./favicon.svg" | relURL }}",
       "sizes": "512x512"
     }
   ]

assets/sw-register.js

@@ -2,6 +2,6 @@
 if (navigator.serviceWorker) {
   navigator.serviceWorker.register(
     "{{ $swJS.RelPermalink }}", 
-    { scope: "{{ "/" | relURL }}" }
+    { scope: "{{ "./" | relURL }}" }
   );
 }