Documentation proofreading

[wackbyte]

Pull Request

Related issue

(No related issue)

What does this PR do?

Proofreads portions of the documentation, attempting to improve its readability.

PR checklist

Please check if your PR fulfills the following requirements:

• [x] 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? (This project seems to be missing a CONTRIBUTING.md)
• [x] Have you made sure that the title is accurate and descriptive of the changes?

Thank you so much for contributing to Meilisearch!

[Kerollmops]

@wackbyte Could you please cargo +nightly fmt the project?

[wackbyte]

Done!