Add js-docs shortcode to ensure consistency between doc and js code

[hannahiss]

Description

• add js-docs shortcode
• update documentation to point on snippets.js and sanitizer.js where relevant:
  • alerts.md => pointing on snippets.js
  • modal.md => pointing on snippets.js
  • toats.md => pointing on snippets.js
  • javascript.md => pointing on sanitizer.js

Motivation & Context

Js-docs shortcode will help avoid copy/paste errors and documentation update oversights

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-38316--twbs-bootstrap.netlify.app/

Direct links:

• https://deploy-preview-38316--twbs-bootstrap.netlify.app/docs/5.3/components/alerts/#live-example
• https://deploy-preview-38316--twbs-bootstrap.netlify.app/docs/5.3/components/modal/#varying-modal-content
• https://deploy-preview-38316--twbs-bootstrap.netlify.app/docs/5.3/components/toasts/#live-example
• https://deploy-preview-38316--twbs-bootstrap.netlify.app/docs/5.3/getting-started/javascript/#sanitizer

Related issues

[XhmikosR]

Nice, looking good so far ❤️

[mdo]

Nice!