Add frequency to matchingStrategy

[NoodleSamaChan]

Pull Request

Related issue

Fixes #594

What does this PR do?

Fixes #594 I also corrected a small typo in the test for LAST

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:

• clippy-check
• integration-tests
• readme-check
• rust-format
• wasm-build
• Yaml linting check