relative paths

so that the build artifacts also work outside of a hosted webserver.
(e.g. directly opening index.html in a browser)

src/components/SmooHeader.vue

@@ -4,7 +4,7 @@
       <img
         alt="Super Mario Odyssey: Online Logo"
         title="Super Mario Odyssey: Online"
-        src="/img/logo.png"
+        src="img/logo.png"
         width="144"
         height="128"
       />

vue.config.js

@@ -1,6 +1,7 @@
 const { defineConfig } = require('@vue/cli-service')
 
 module.exports = defineConfig({
+  publicPath            : '',
   transpileDependencies : true,
   runtimeCompiler       : true,
   pages                 : {