fix: break long lines to comply with markdown linting rules

- Reformat lines exceeding 80 character limit in README.md
- Break long lines in docs/how-to/install-kubernetes.md
- Improve readability while maintaining markdown formatting

https://claude.ai/code/session_01UJodgmvR7sQz79waMx2bq4

Author: claude

README.md

@@ -60,15 +60,18 @@ bin/production.sh up -d --wait
 bin/production.sh run --rm web setup.sh
 ```
 
-After setup, the management interface is at `http://127.0.0.1:81/manager/` and webmail at `http://127.0.0.1:81/webmail/`.
+After setup, access the management interface at
+`http://127.0.0.1:81/manager/` and webmail at `http://127.0.0.1:81/webmail/`.
 
-For a complete walkthrough, see the [Getting Started tutorial](docs/tutorials/getting-started.md).
+For a complete walkthrough, see the
+[Getting Started tutorial](docs/tutorials/getting-started.md).
 
 ## Setup
 
 `docker-mailserver` can be set up using Docker or Kubernetes.
 
-For detailed installation instructions, see the [Installation Guide](docs/installation.md) in the documentation.
+For detailed installation instructions, see the
+[Installation Guide](docs/installation.md).
 
 ## Screenshots
 

docs/how-to/install-kubernetes.md

@@ -1,8 +1,10 @@
 # How to Install on Kubernetes
 
-This guide describes how to deploy docker-mailserver on Kubernetes with Kustomize. An external MySQL-compatible database is required; the kustomization does not provision a database.
+This guide describes how to deploy docker-mailserver on Kubernetes with
+Kustomize. An external MySQL-compatible database is required; the
+kustomization does not provision a database.
 
-A full example is in [example-configs/kustomize/external-db-and-https-ingress](https://github.com/jeboehm/docker-mailserver/tree/main/docs/example-configs/kustomize/external-db-and-https-ingress).
+A full example is in [example-configs/kustomize/external-db-and-https-ingress](../example-configs/kustomize/external-db-and-https-ingress/).
 
 ## Prerequisites
 
@@ -14,9 +16,14 @@ A full example is in [example-configs/kustomize/external-db-and-https-ingress](h
 
 ### 1. Configure environment (ConfigMap and Secrets)
 
-Use `.env.dist` as a reference for the required variables. Create a Kubernetes ConfigMap from the non-sensitive values and Kubernetes Secrets for sensitive values (database credentials, passwords, API keys). See [Environment variables reference](../reference/environment-variables.md) for the full variable list.
+Use `.env.dist` as a reference for required variables. Create a Kubernetes
+ConfigMap for non-sensitive values and Secrets for sensitive values
+(credentials, passwords, API keys). See [Environment variables reference](../reference/environment-variables.md) for the full list.
 
-The example configuration in [example-configs/kustomize/external-db-and-https-ingress](../example-configs/kustomize/external-db-and-https-ingress/) shows how to structure these resources.
+See the
+[example-configs/kustomize/external-db-and-https-ingress](../example-configs/kustomize/external-db-and-https-ingress/)
+directory for a sample configuration showing how to structure these
+resources.
 
 ### 2. Create namespace
 
@@ -30,7 +37,9 @@ kubectl create namespace mail
 bin/create-tls-certs.sh
 ```
 
-This writes a self-signed certificate and key to `config/tls/tls.crt` and `config/tls/tls.key`. For production, use certificates from a CA (e.g. cert-manager with Let's Encrypt) instead.
+This writes a self-signed certificate to `config/tls/tls.crt` and key to
+`config/tls/tls.key`. For production, use CA certificates (e.g.
+cert-manager with Let's Encrypt) instead.
 
 ### 4. Create TLS secret
 
@@ -62,20 +71,24 @@ Wait until all pods are running and healthy.
 kubectl exec -n mail -it deployment/web -c php-fpm -- setup.sh
 ```
 
-Use the wizard to set initial configuration, create the first email address, and create an admin user.
+Use the wizard to set initial configuration, create the first email
+address, and create an admin user.
 
 ### 8. Access the management interface
 
 Use your configured ingress and the admin credentials from the wizard.
 
 ## Post-installation
 
-- Configure DNS and TLS as for Docker. See [How to configure DNS](configure-dns.md) and [How to configure TLS certificates](configure-tls.md).
+- Configure DNS and TLS like Docker deployment. See [How to configure DNS](configure-dns.md) and [How to configure TLS certificates](configure-tls.md).
 - Change `DOVEADM_API_KEY` from default if using observability (v7.3+).
 
 ## Troubleshooting
 
-- **Pods not starting:** Check pod logs with `kubectl logs -n mail <pod-name>` and events with `kubectl describe pod -n mail <pod-name>`.
-- **Database errors:** Verify database connectivity and that the `MYSQL_*` variables in the ConfigMap/Secrets are correct.
-- **TLS errors:** Confirm the `tls-certs` secret exists in the `mail` namespace and the certificate paths are correct.
+- **Pods not starting:** Check logs with `kubectl logs -n mail <pod-name>`
+  and events with `kubectl describe pod -n mail <pod-name>`.
+- **Database errors:** Verify database connectivity and that the
+  `MYSQL_*` variables in ConfigMap/Secrets are correct.
+- **TLS errors:** Confirm the `tls-certs` secret exists in the `mail`
+  namespace and certificate paths are correct.
 - **Setup wizard fails:** Ensure the web pod is running (`kubectl get pods -n mail`) before running the exec command.

docs/reference/environment-variables.md

@@ -46,10 +46,10 @@ When using the Redis service provided by docker-mailserver compose or kustomize,
 
 Set `RELAYHOST` to `[hostname]:port` to route all outgoing mail through an external SMTP server. Leave unset to deliver directly.
 
-| Variable            | Default        | Description                       |
-| ------------------- | -------------- | --------------------------------- |
-| `RELAYHOST`         | _(disabled)_   | SMTP relay host for outgoing mail (e.g. `[smtp.example.com]:587`) |
-| `RELAY_PASSWD_FILE` | _(disabled)_   | Path to relay authentication file (inside the MTA container) |
+| Variable            | Default      | Description                                                       |
+| ------------------- | ------------ | ----------------------------------------------------------------- |
+| `RELAYHOST`         | _(disabled)_ | SMTP relay host for outgoing mail (e.g. `[smtp.example.com]:587`) |
+| `RELAY_PASSWD_FILE` | _(disabled)_ | Path to relay authentication file (inside the MTA container)      |
 
 ### Filter