Update README to reflect project changes.

[Aedrus]

README is based on a pre-defined structure. All that needs to be done is to input the correct links, data, and images for a fully fleshed-out README.

• Add in links for various pages including documentation, guidelines, and more.
• Add clear and well-written descriptions for both the introduction and "how to" sections.
• Add a well-designed preview image at the top of the readme.