Move the ts-results fork documentation out of the readme

[jstasiak]

Following up on the work started in [1].

Applied some necessary changes to the content since we're migrating from Markdown to reStructuredText.

Following the Diataxis framework[2] for structuring the documentation.

[1] 633ccad330e8 ("Set up an initial documentation structure (#81)") [2] https://diataxis.fr/

[jstasiak]

We're following https://diataxis.fr/ here.

Open question, should it be "Explanations" or maybe something else?

• Key topics
• Background
• Explanation (note: no "s" at the end)
• ...

[jstasiak]

Yup, I'll change to Explanation