feature/add-upgrade-doc (#63)

* add-oidc-docs-2

* Update content/en/docs/oidc.md

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

* add upgrade doc

* Update content/en/docs/upgrade.md

Co-authored-by: Andrei Kvapil <[email protected]>

* fix

---------

Co-authored-by: Andrei Kvapil <[email protected]>
Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

content/en/docs/upgrade.md

@@ -0,0 +1,53 @@
+---
+title: "Upgrade Cozystack"
+linkTitle: "Upgrade"
+description: "Upgrade Cozystack system components."
+weight: 60
+---
+
+## Upgrade Cozystack
+
+### Check current cozystack status
+```bash
+kubectl get hr -A | grep -v "True"
+```
+Repair helmreleases if nessesary.  
+Make sure that the cozystack config map contains all the necessary variables.
+
+```bash
+kubectl get configmap -n cozy-system cozystack -oyaml
+```
+Example output:
+```yaml
+apiVersion: v1
+data:
+  api-server-endpoint: https://33.44.55.66:6443
+  #bundle-enable: telepresence if nessesary
+  bundle-name: paas-full
+  ipv4-join-cidr: 100.64.0.0/16
+  ipv4-pod-cidr: 10.244.0.0/16
+  ipv4-pod-gateway: 10.244.0.1
+  ipv4-svc-cidr: 10.96.0.0/16
+  # oidc-enabled: "true" if nessesary
+  root-host: example.org
+kind: ConfigMap
+...
+```
+And add missing key: value data.
+
+### Apply new version
+```bash
+version=vX.Y.Z
+kubectl apply -f https://github.com/aenix-io/cozystack/raw/$version/manifests/cozystack-installer.yaml
+```
+
+### Check cozystack status
+```bash
+kubectl get pods -n cozy-system
+kubectl get hr -A | grep -v "True"
+```
+
+If pod status is failure, check logs.
+```bash
+kubectl logs deploy/cozystack -n cozy-system --previous
+```