Adds troubleshooting guide

Signed-off-by: michal.gubricky <michal.gubricky@dnation.cloud>

docs/troubleshooting.md

@@ -0,0 +1,29 @@
+# Troubleshooting
+
+This guide explains general info on how to debug issues if a cluster creation fails.
+
+## providerClient authentication err
+
+If you are using https, and when you encounter issue like:
+
+```
+kubectl logs -n cspoo-system logs -l control-plane=capo-controller-manager <cspo-controller-manager-pod>
+...
+E0415 13:54:50.329787 1311424 openstacknodeimagerelease_controller.go:164] "failed to create a provider client" err="Get \"https://xxxxx:5000/v3/auth/tokens: x509: certificate signed by unknown authority..."
+...
+```
+
+ you must specify the CA certificate in your secret, which contains the access data to the OpenStack intance, then secret should looks similiar to this example:
+
+ ```bash
+apiVersion: v1
+data:
+  caCert: <PEM_ENCODED_CA_CERT>
+  clouds.yaml: <ENCODED_CLOUDS_YAML>
+kind: Secret
+metadata:
+  labels:
+    clusterctl.cluster.x-k8s.io/move: "true"
+  name: "openstack"
+  namespace: cluster
+ ```