publish cluster template as release asset (#51)

publish cluster template as release asset so that clusterctl can
discover it.

Author: bwagner5

.goreleaser.yaml

@@ -68,6 +68,7 @@ checksum:
     - glob: ./_artifacts/helm/*.tgz
     - glob: ./_artifacts/infrastructure-components.yaml
     - glob: ./_artifacts/metadata.yaml
+    - glob: ./templates/cluster-template.yaml
 
 # Attach the clusterctl provider artifacts to the GitHub release so
 # `clusterctl init --infrastructure oxide` can discover and install the
@@ -80,6 +81,7 @@ release:
   extra_files:
     - glob: ./_artifacts/infrastructure-components.yaml
     - glob: ./_artifacts/metadata.yaml
+    - glob: ./templates/cluster-template.yaml
 
 # NOTE: helm charts are pushed to the OCI registry by the `release` Makefile
 # target after goreleaser finishes. A custom publisher can't do it: goreleaser