docs: add comment explainer

Author: hacdias

examples/gateway/common/handler.go

@@ -17,6 +17,9 @@ func NewHandler(gwAPI gateway.IPFSBackend) http.Handler {
 		// If you set DNSLink to point at the CID from CAR, you can load it!
 		NoDNSLink: false,
 
+		// For these examples we have the trusted mode enabled by default. That is,
+		// all types of requests will be accepted. By default, only Trustless Gateway
+		// requests work: https://specs.ipfs.tech/http-gateways/trustless-gateway/
 		TrustedMode: true,
 
 		// Initialize the public gateways that we will want to have available through