What does this PR change? What problem does it solve?

The HTML created by hugo has two minor problems (report here):

1. Error: Element ul not allowed as child of element span in this context.
2. Error: No p element in scope but a p end tag seen.

This PR fixes both by replacing the <span> with a <div> in header.html and making sure that <p> tags are not nested in home_info.html.

Was the change discussed in an issue or in the Discussions before?
Error 1 was briefly discussed in #599, I found the other one.

PR Checklist

• This change adds/updates translations and I have used the template present here.
• I have enabled maintainer edits for this PR.
• I have verified that the code works as described/as intended.
• This change adds a Social Icon which has a permissive license to use it.
• This change does not include any CDN resources/links.
• This change does not include any unrelated scripts such as bash and python scripts.
• This change updates the overridden internal templates from HUGO's repository.