[Feature] Add HTML meta nofollow parameter

[stdevel]

I confirm:

• I have read the Hugo Clarity theme documentation.
• I have reviewed other issues in this repository, and this feature has not already been requested.

Type of feature (check all that apply)

• Site functionality
• Design (styling)
• Site performance
• Accessibility
• Translations and internationalization (i18n)
• Code improvements
• Other (please describe below)

Describe the feature

Currently, all pages or posts can be indexed by search engines.

Preferred solution

Having an option to disable indexing for particular pages or posts would be a benefit. This could be implemented by adding an parameter to the front matter that will simply render the following HTML meta tag:

<meta name="robots" content="noindex" />

Alternatives

No response

Additional Context

No response