Add logo for cert-manager

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

Author: alexellis

_posts/2021-05-19-istio-functions.md

@@ -308,10 +308,19 @@ kubectl get svc -n istio-system istio-ingressgateway
 NAME                   TYPE           CLUSTER-IP       EXTERNAL-IP
 istio-ingressgateway   LoadBalancer   10.106.200.195   <pending>
 ```
-If you're running within a private VPC, on-premises or on your laptop, then you will need to get a public IP for Istio through the inlets-operator. See a full guide to [setting up the inlets-operator with Istio](https://blog.alexellis.io/a-bit-of-istio-before-tea-time/) to provide an IP via a secure tunnel. That will then change `<pending>` to a fully accessible IP.
+
+<img src="https://docs.inlets.dev/images/inlets-oss-logo.svg" width="140px" alt="inlets logo">
+
+> Inlets can enable LoadBalancers and Controllers for local and private Kubernetes clusters
+
+If you're running within a private VPC, on-premises or on your laptop, then you will need to get a public IP for Istio through the [inlets-operator](https://docs.inlets.dev/images/inlets-oss-logo.svg). See a full guide to [setting up the inlets-operator with Istio](https://blog.alexellis.io/a-bit-of-istio-before-tea-time/) to provide an IP via a secure tunnel. That will then change `<pending>` to a fully accessible IP.
 
 Otherwise, copy the IP or CNAME issued to you under `EXTERNAL-IP` and create your DNS entry. I'll be using the domain `faas.o6s.io`.
 
+<img src="/images/2021-05-istio/cert-manager-icon.png" width="100px" alt="cert-manager logo">
+
+> [cert-manager](https://cert-manager.io/) is a CNCF project for obtaining, renewing and managing TLS certificates
+
 You can get a TLS certificate to serve traffic over HTTPS using cert-manager.
 
 ```bash