docs: README work

[pelasgus]

• OS X has not been called that since 2015, fixed it for you.
• Logical separation of code blocks
• Etymological fixes; namely requirements and prerequisites really stood out
• Removed general fluff and rumbling

Considering this aims to be a serious technical document, the tone and style of writing do not really suit it. thus:

• Third person removed where applicable
• English does not posses a "royal we" as called by linguistics(Think french on for example, thus first person plural should be avoided), thus has been removed from sight and replaced with passive voice where applicable to exude the correct tonality.

[pelasgus]

I will add a flake.nix as well for dev-shells and a justfile to simplify the whole build/test process. The repository as is, has been configured to work with lorri and direnv.