title: Build vue project through vue-cli-service build while missing . in file path
body: <p>My vue project is completed.
  When I run script 'npm run build',which is 'vue-cli-service build', I can get a pack of output files.
  However in index.html file, all js and css files' path are not right.
  for example:</p>
  
  <pre><code>&lt;script src=js/chunk-vendors.40fba41b.js&gt;
  </code></pre>
  
  <p>Correct one should be:</p>
  
  <pre><code>&lt;script src="./js/chunk-vendors.40fba41b.js"&gt;
  </code></pre>
  
  <p>I googled a lot. Some said to modify webpack's config, which I found out impossible since vue-cli3 does not provide such config file. Some said it can be done by adding baseurl in vue.config.js file like this:</p>
  
  <pre><code>module.exports = {
      baseUrl: "./",
  }
  </code></pre>
  
  <p>When I set baseUrl as './', the problem remains.
  When I change baseUrl to "somecode/", the output files would be:</p>
  
  <pre><code>&lt;script src=somecode/js/chunk-vendors.40fba41b.js&gt;
  </code></pre>
  
  <p>I am really confused by it.
  Why and how to fix this problem?
  Thanks in advance.</p>