This change extracts the landing page from the web interface in order to
separate the development of the two. This allows the landing page to be
developed independently of the actual OpenDC web application.

This change updates the frontend to use the FontAwesome 5 React library
that renders SVG icons as opposed to CSS icon fonts. This migration
resolves a couple of issues we had with server-side rendering of the
previous FontAwesome icons.

This change updates the structure of the OpenDC frontend in order to
improve the maintainability of the frontend.

This change updates the frontend codebase by moving the component
styling into CSS module files as opposed to the global styles which we
used before. In addition, I have changed the syntax to the newer SCSS
syntax, which is more similar to CSS.

These changes reduces the styling conflicts that can occur between
components and allows us to migrate to systems that do not support
importing global styles in components. Moreover, we can benefit from
treeshaking using CSS modules.