README Rework

A small README rework.

Please check out the Preview

1. The original txt version is still available as README
2. Formatted as Markdown
3. Added header link section to useful resources
4. Extended the topics section
5. Sectioned all the paragraphs
6. Abstracted away direct links into it's own section
7. Added table / code sections
8. Added highlighting to context clues

I adjusted the present tense writing in the Stability section partially.

I would love to have some feedback regarding what may have changed or
could be worded differently to present the current state of the project better.