Adds guide to use upstream main image

docs/guides-using-latest-image.md

@@ -0,0 +1,26 @@
+You can test a feature that was not yet released using the following method:
+
+1. Create a `values.yaml` file with the following content:
+   
+```
+replicaCount: 1
+
+image:
+  repository: ghcr.io/external-secrets/external-secrets
+  pullPolicy: IfNotPresent
+  # -- The image tag to use. The default is the chart appVersion.
+  tag: "main"
+
+# -- If set, install and upgrade CRDs through helm chart.
+installCRDs: false
+```
+
+2. Install the crds
+```
+make crds.install
+```
+
+3. Install the external-secrets Helm chart indicating the values file created before:
+```
+helm install external-secrets external-secrets/external-secrets -f values.yaml
+``` 

hack/api-docs/mkdocs.yml

@@ -35,6 +35,7 @@ nav:
     - Common K8S Secret Types: guides-common-k8s-secret-types.md
     - Multi Tenancy: guides-multi-tenancy.md
     - Metrics: guides-metrics.md
+    - Using Latest Image: guides-using-latest-image.md
   - Provider:
     - AWS:
       - Secrets Manager: provider-aws-secrets-manager.md