Doc optimization for GSC and mobile viewers

[OlufunkeMoronfolu]

Here is what to expect with this PR:

• Fixed the long-standing mobile unresponsiveness. Now, when on small screens, users can see the hamburger menu, which opens the sidebar when clicked. Test by minimizing your screen.
• The doc content is now reordered to enable better crawling and should solve our crawling problem with Google. Test this by using either the browser's:
  • View page source
  • Inspect