Added ToC & Improved Readability

[MarkSchmidty]

I added a table of contents, cleaned up some confusing language, and made the "tags" full words for better readability ("bare" not "B" for example).

[nichtdax]

Thank for proposing Rating system to replace Tag system. I will take your word in consideration but I can't merge the PR. Best I can do is to just merge

• The rewritten introduction
• The ToC

[MarkSchmidty]

It's your thing man, go ahead. :)

[nichtdax]

Based on your proposal, I just revert it's back to Tags (because it's shorter), and I use Standard for Medium.