Merge ~mthaddon/charm-k8s-ingress/+git/charm-k8s-ingress:readme-define-controller into charm-k8s-ingress:master

[Tom Haddon]

Rewrite description in README to define how this charm interacts with an ingress controller to provide ingress

Rewrite description in README to define how this charm interacts with an ingress controller to provide ingress

[🤖 Canonical IS Merge Bot (canonical-is-mergebot)]

This merge proposal is being monitored by mergebot. Change the status to Approved to merge.

[🤖 Canonical IS Merge Bot (canonical-is-mergebot)]

Change successfully merged at revision 1fec55d3fc1c3aa3dc127e34bf2b7435eba7a072

diff --git a/README.md b/README.md
index c24b8cc..1a785a1 100644
--- a/README.md
+++ b/README.md
@@ -2,11 +2,16 @@
 
 ## Description
 
-This charm is intended to provide an nginx ingress for sidecar charms using the
-Operator Framework until such time as Juju can expose the relevant primitives
-to enable charms to configure an ingress natively via Juju (e.g. with TLS as
-required, with session affinity as required, allowing for upload of a given
-size, etc.).
+This charm generates an Nginx Ingress resource for sidecar charms using the
+Operator Framework. This resource can then be used by an Nginx Ingress Controller
+in a Kubernetes cluster to expose HTTP and HTTPS routes from outside the cluster
+to a charm running within the cluster. As such, this charm requires your
+Kubernetes cluster to have an Nginx Ingress Controller already deployed to it.
+
+For more information about Ingress Controllers, [see here](https://kubernetes.io/docs/concepts/services-networking/ingress-controllers/).
+To enable an Nginx Ingress Controller on MicroK8s, just run `microk8s enable ingress`,
+or if you're using [Charmed Kubernetes](https://ubuntu.com/kubernetes) you can
+enable it with `juju expose kubernetes-worker`.
 
 ## Usage