docs: warns about windows correct files encoding

[jefersoneiji]

Description

Warn windows users the correct encoding to use.

Motivation and Context

#4085 (comment)

Usage examples

// commitlint.config.js
module.exports = {};

echo "your commit message here" | commitlint # fails/passes

How Has This Been Tested?

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 change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

[codesandbox-ci]

This pull request is automatically built and testable in CodeSandbox.

To see build info of the built libraries, click here or the icon next to each commit SHA.

[escapedcat]

Thanks!