Add basic webserver skeleton with healthcheck

internal/handlers/healthcheck.go

@@ -0,0 +1,12 @@
+package handlers
+
+import (
+	"net/http"
+)
+
+func (s *Handlers) HandleHealthCheck() http.HandlerFunc {
+	return func(w http.ResponseWriter, _ *http.Request) {
+		resp := s.hc.Healthcheck()
+		s.respondJSON(w, resp, http.StatusOK)
+	}
+}