Docs: add ngx-bootstrap to JavaScript frameworks list

[julien-deramond]

Description

This PR adds ngx-bootstrap to our JavaScript frameworks list. It works well with Bootstrap 5, as an equivalent number of stars compared to ng-bootstrap, and is widely used by the Bootstrap community.

Type of changes

• [x] Docs enhancement (non-breaking change)

Checklist

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

Live previews

• https://deploy-preview-40932--twbs-bootstrap.netlify.app/docs/5.3/getting-started/javascript/#usage-with-javascript-frameworks

Related issues

Closes #40921

[coliff]

Thanks for this! Looks good 👍