Doc fix: Use hyphen to install prospector with mypy and bandit in pre-commit

[jdechicchis]

Doc fix to use - instead of _ to install mypy/bandit with prospector in pre-commit.

Description

See #633. From this discussion seems to be related to how poetry resolves optional dependencies

Related Issue

#633

Motivation and Context

Makes docs clearer.

How Has This Been Tested?

Used this updated pre-commit config in my own project, which was previously experiencing dependency install issues.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• My change requires a change to the dependencies
• I have updated the dependencies accordingly
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[Pierre-Sassoulas]

Thank you !