Fix links, formulas, add payout image,

BugFix Merge Request

Related Issue

resolves #60 (closed)

Description of Bug and Fix

before:

after: they are properly rendered:

Description of added Features

• working links
• also added the payout graph. Unfortunately, it is so small that is unreadable and I couldn't figure out how to increase the size.
• ToC below abstract
  • chapter 3 about roadmap & implementation is excluded because it was removed with !62 (merged)
• navigation items at bottom of pages

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