+ support google adsense and AI summarize

[lispking]

PR Checklist

• [x] The commit message follows guidelines for NexT.
• [x] The changes have been tested (for bug fixes / features).
• [x] Docs in NexT website have been added / updated (for features).

PR Type

• [ ] Bugfix.
• [x] Feature.
• [ ] Improvement.
• [ ] Code style update (formatting, linting).
• [ ] Refactoring (no functional changes).
• [ ] Documentation.
• [ ] Translation.
• [ ] Other... Please describe:

What is the new behavior?

Support google adsense

How to use?

In NexT _config.yml:

google_adsense: # <client_id>