Docs: add descriptions for Webpack, Parcel and Vite

[TommasoAllegretti]

Description

In response to #40506, I added a brief description of the tools on the Webpack, Parcel and Vite pages.

Type of changes

• Documentation 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-40714--twbs-bootstrap.netlify.app/