Upate README

[PSchmiedmayer]

Problem

Thank you for merging the #27 PR @lukaskollmer!

While looking at the merged README I noticed that a few symbols don't contain a link. Nothing major but would be nice to address now that we should be able to link them in the Swift Package index; sorry for missing this in the PR review.

Solution

Smaller things I noticed in the README that might also apply to some DocC articles.

• Add links to all code symbols in the markdown
• Use research paper title capitalization for section headers and other titles such as PR titles.
• Fix the Important: formatting in the README
• Remove "Example: " from the title of the headings.

Additional context

No response

Code of Conduct

• I agree to follow this project's Code of Conduct and Contributing Guidelines