Supports `rankingScoreThreshold` search parameter

[aweidner]

Pull Request

Related issue

Fixes #986

What does this PR do?

• Adds an integration test for a search using rankingScoreThreshold
• Updates the code example file to include a translated call for search involving rankingScoreThreshold

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)?
• [x] Have you read the contributing guidelines?
• [x] Have you made sure that the title is accurate and descriptive of the changes?

Thank you so much for contributing to Meilisearch!

[meili-bors[bot]]

Build succeeded:

• integration-tests (3.10)
• integration-tests (3.11)
• integration-tests (3.12)
• integration-tests (3.8)
• integration-tests (3.9)
• mypy
• pylint