Fix GraphiQL font rendering

The GraphiQL page-level font-family CSS rules are not applying because the `renderGraphiQL.js` page uses a JS-type comment in a `<style>` block. This PR is a quick fix to change to use the CSS style comment `/* ... */` so that the first CSS rule doesn't get skipped.

Author: Sam Parsons

src/renderGraphiQL.js

@@ -69,7 +69,7 @@ add "&raw" to the end of the URL within a browser.
  }
  </style>
  <style>
- // graphiql/graphiql.css
+ /* graphiql/graphiql.css */
  ${loadFileStaticlyFromNPM('graphiql/graphiql.css')}
  </style>
  <script>