Docs: Simplify ids for checks, radios and switches

[coliff]

Description

Minor thing but no need for 'flex' being prefixed in the examples.

Motivation & Context

With them being shorter may mean a few examples won't need horizontal scrollbars :-)
keeps things simpler and slightly easier to scan

Type of changes

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

Checklist

• I have read the contributing guidelines
• My code follows the code style of the project (using npm run lint)
• My change introduces changes to the documentation
• I have updated the documentation accordingly
• I have added tests to cover my changes
• All new and existing tests passed

Live previews

• https://deploy-preview-41228--twbs-bootstrap.netlify.app/

[julien-deramond]

Thanks, @coliff, for these modifications! I've made some adjustments:

• Updated ids, fors, and names to use camel casing for consistency across the docs.
• Applied your change to the Cheatsheet examples as well.

Could you please review to ensure everything looks correct? Once you confirm, I'll proceed with merging. :)

[coliff]

thanks - looks good!