Configure K8s deployment for easy LetsEncrypt verification.

This is not the certificate setup we will use in production. I'd like to
merge this configuration as a reference point because this is the
easiest way to handle manual LetsEncrypt verification within the
cluster.

This allows NGINX to serve static files over HTTP from the
".well-known/acme-challenge" directory, which is necessary for certbot
validation of domain ownership.

deploy/azure/acme-challenges.yml

@@ -0,0 +1,8 @@
+apiVersion: v1
+data:
+  foo: |
+    bar
+kind: ConfigMap
+metadata:
+  name: acme-challenges
+  namespace: atat