fix: update content security header

  Strict-Transport-Security: max-age=31536000; includeSubDomains; preload

  X-Content-Type-Options: nosniff

  X-XSS-Protection: 1; mode=block

  Content-Security-Policy: default-src 'self'; frame-ancestors https://jamstackthemes.dev; manifest-src 'self'; connect-src 'self'; font-src 'self'; img-src 'self' data:; script-src 'self'; style-src 'self'

  Content-Security-Policy: default-src 'self'; frame-ancestors https://jamstackthemes.dev; manifest-src 'self'; connect-src 'self'; font-src 'self'; img-src 'self' data:; script-src 'self' 'nonce-wPV5wYvXV9ifrqhyVhpMHg==' 'unsafe-inline'; style-src 'self'

  X-Frame-Options: SAMEORIGIN

  Referrer-Policy: strict-origin

  Feature-Policy: geolocation 'self'

  {{ end -}}

  {{ if .Site.Params.options.kaTex -}}

    <script src="{{ $katex.Permalink }}" defer></script>

    <script src="{{ $katexAutoRender.Permalink }}" onload="renderMathInElement(document.body);" defer></script>

    <script src="{{ $katexAutoRender.Permalink }}" onload="renderMathInElement(document.body);" nonce="wPV5wYvXV9ifrqhyVhpMHg==" defer></script>

  {{ end -}}

  {{ if .Site.Params.options.flexSearch -}}

    <script src="{{ $index.Permalink }}" defer></script>