[I2-30] Hamburger Side Menu

[TR-04]

• Used dom portal to render hamburger at document body instead of at nav
  • why is portal needed? Hamburger is added in navbar.tsx, so the blur-grey backdrop only affects the nav. Hence we move the location of the hamburger using a portal so backdrop affects all components
  • why not place hamburger at index.tsx? Our hamburger icon is placed on the navbar, and will follow the navbar around. So, click detection is in navbar.tsx. Our x button is place in hamburger.tsx and thus so is close detection. Our nav handles closing. So we pass props back to nav. But this means we need to redefine every nav with these new props.
• Quick exit using Esc or tapping outside of sidemenu
• Scroll bar padding offset added
• Socials added to bottom of sidemenu