Docs: use consistent HTML elements in Utilities > Background page

[julien-deramond]

Description

This PR brings more consistency to our Utilities > Background page by using the same HTML element everywhere for the same rendering.

@patrickhlauke I've used <div>s because the entire page was already using mostly <div>s. However, I'm wondering, in terms of documentation accessibility, if it wouldn't be better to use <p>s instead everywhere. What do you think?

Motivation & Context

Consistency.

Type of changes

• Docs refactoring (non-breaking change)

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
• (N/A) I have added tests to cover my changes
• All new and existing tests passed

Live previews

• https://deploy-preview-39519--twbs-bootstrap.netlify.app/docs/5.3/utilities/background/

[patrickhlauke]

However, I'm wondering, in terms of documentation accessibility, if it wouldn't be better to use <p>s instead everywhere. What do you think?

won't make any practical difference, so this is good to go