docs: Added details about helm LTS versioning

Author: mariadb-stefangenov

tools/mariadb-enterprise-operator/installation/helm.md

@@ -13,6 +13,15 @@ MariaDB Enterprise Kubernetes Operator is splitted into two different helm chart
 * `mariadb-enterprise-operator-crds`: Bundles the [CustomResourceDefinitions](https://kubernetes.io/docs/concepts/extend-kubernetes/api-extension/custom-resources/) required by the operator.
 * `mariadb-enterprise-operator`: Contains all the template manifests required to install the operator. Refer to the [operator helm values](helm.md#operator-helm-values) section for detailed information about the supported values.
 
+## Long-Term Support Versions
+
+MariaDB Enterprise Kubernetes Operator provides stable Long-Term Support (LTS) versions.
+
+| Version | Supported Kubernetes Versions | Description | Latest Version |
+|---------|------------------------------|-------------|--------------|
+| `latest` | `>=1.26.0-0` | The latest cutting-edge version of the MariaDB Enterprise Kubernetes Operator. | `25.10.0` |
+| `25.10` | `>=1.26.0-0 <= 1.34.0-0` | LTS 25.10. It was tested to work up to kubernetes v1.34 but newer versions may also be supported. | `25.10.0` |
+
 ## Control-plane
 
 The operator extends the Kubernetes control plane and consists of the following components deployed via Helm:
@@ -32,6 +41,14 @@ helm repo add mariadb-enterprise-operator https://operator.mariadb.com
 helm install mariadb-enterprise-operator-crds mariadb-enterprise-operator/mariadb-enterprise-operator-crds
 ```
 
+If you instead wish to install a specific LTS release, you can do:
+
+```sh
+helm install --version "25.10.*" mariadb-enterprise-operator-crds mariadb-enterprise-operator/mariadb-enterprise-operator-crds
+```
+
+Where: `--version "25.10.*"` installs the most recent available release within the 25.10 series.
+
 ## Installing the operator
 
 The first step is to prepare a `values.yaml` file to specify your previously configured [customer credentials](../customer-access-to-docker-mariadb-com.md#customer-credentials):
@@ -66,6 +83,17 @@ helm install mariadb-enterprise-operator mariadb-enterprise-operator/mariadb-ent
   --set metrics.enabled=true --set webhook.cert.certManager.enabled=true
 ```
 
+If you instead wish to install a specific LTS release, you can do:
+
+```diff
+helm install mariadb-enterprise-operator mariadb-enterprise-operator/mariadb-enterprise-operator \
+  -f values.yaml \
+  --set metrics.enabled=true --set webhook.cert.certManager.enabled=true
+  --version "25.10.*"
+```
+
+Where: `--version "25.10.*"` installs the most recent available release within the 25.10 series.
+
 Refer to the [operator helm values](helm.md#operator-helm-values) section for detailed information about the supported values.
 
 ## Deployment modes
@@ -100,6 +128,11 @@ helm install mariadb-enterprise-operator \
 Make sure you read and understand the [updates documentation](../updates.md) before proceeding to update the operator.
 {% endhint %}
 
+{% hint style="warning" %}
+To install a Long-Term Support (LTS) version instead, replace `<new-version>` with your desired LTS release.
+For example: `--version "25.10.*"` will automatically install the latest available patch within that LTS series.
+{% endhint %}
+
 The first step is upgrading the CRDs that the operator depends on:
 
 ```sh