Is your feature request related to a problem? Please describe.
The tailwind-nextjs-starter-blog template does not define any security headers currently.

Describe the solution you'd like
Next.js makes it possible to define custom security headers.

The X-Frame-Options, X-Content-Type-Options and the Referrer-Policy headers should be always possible.
The Content-Security-Policy and the Permissions-Policy header would also be nice, but it might be necessary for users to change them as they develop their website.
The Strict-Transport-Security header is automatically added by Vercel, but other hosters might not include it.

Describe alternatives you've considered
For some of the headers there are no alternatives. And even if there were alternatives, including them would be a good idea for a better security.