Switch main report page to better example

This is still pulling from our generic district mock, but it's still
better than what we had. This also includes adding static content
hosting for the bootstrap content on the public domain.

htmlpage/response.go

@@ -6,6 +6,33 @@ import (
 	"github.com/rs/zerolog/log"
 )
 
+// Custom ResponseWriter to track Content-Type
+type customResponseWriter struct {
+	http.ResponseWriter
+	contentType string
+	wroteHeader bool
+}
+
+func (crw *customResponseWriter) WriteHeader(code int) {
+	crw.wroteHeader = true
+	crw.ResponseWriter.WriteHeader(code)
+}
+
+func (crw *customResponseWriter) Header() http.Header {
+	return crw.ResponseWriter.Header()
+}
+
+func (crw *customResponseWriter) Write(b []byte) (int, error) {
+	if !crw.wroteHeader {
+		if crw.contentType == "" {
+			crw.contentType = http.DetectContentType(b)
+			crw.ResponseWriter.Header().Set("Content-Type", crw.contentType)
+		}
+		crw.WriteHeader(http.StatusOK)
+	}
+	return crw.ResponseWriter.Write(b)
+}
+
 // Respond with an error that is visible to the user
 func respondError(w http.ResponseWriter, m string, e error, s int) {
 	log.Warn().Int("status", s).Err(e).Str("user message", m).Msg("Responding with an error")