Remove README.md API section, refactor Documentation section

[flevi29]

Pull Request

What does this PR do?

• removes README.md API section
• refactors Documentation section

PR checklist

Please check if your PR fulfills the following requirements:

• Does this PR fix an existing issue, or have you listed the changes applied in the PR description (and why they are needed)?
• Have you read the contributing guidelines?
• Have you made sure that the title is accurate and descriptive of the changes?

Thank you so much for contributing to Meilisearch!

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 99.02%. Comparing base (69e056c) to head (31f6d49).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1866   +/-   ##
=======================================
  Coverage   99.02%   99.02%           
=======================================
  Files          18       18           
  Lines        1435     1435           
  Branches      303      303           
=======================================
  Hits         1421     1421           
  Misses         14       14           

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[flevi29]

@Strift We must get rid of this README.md API section. It is too much of a headache to maintain. Already have an issue regarding it: #1929