Add installation via docker compose (MVP 1)

- Add markdown tabs blocks
- Fix [Issue 604](https://github.com/chatmail/relay/issues/604)
- Add `--skip-dns-check` argument to `cmdeploy run` command
- Add `--force` argument to `cmdeploy init` command
- Add startup for `fcgiwrap.service`
- Add extended check when installing `unbound.service`
- Add configuration parameters (`is_development_instance`, `use_foreign_cert_manager`, `acme_email`, `change_kernel_settings`, `fs_inotify_max_user_instances_and_watchers`)

README.md

@@ -74,22 +74,23 @@ Please substitute it with your own domain.
    ```
     git clone https://github.com/chatmail/relay
     cd relay
+   ```
+
+### Manual installation
+1. On your local PC, create chatmail configuration file `chatmail.ini`:
+
+   ```
     scripts/initenv.sh
-   ```
-
-3. On your local PC, create chatmail configuration file `chatmail.ini`:
-
-   ```
     scripts/cmdeploy init chat.example.org  # <-- use your domain 
    ```
 
-4. Verify that SSH root login to your remote server works:
+2. Verify that SSH root login to your remote server works:
 
    ```
     ssh root@chat.example.org  # <-- use your domain 
    ```
 
-5. From your local PC, deploy the remote chatmail relay server:
+3. From your local PC, deploy the remote chatmail relay server:
 
    ```
     scripts/cmdeploy run
@@ -99,6 +100,9 @@ Please substitute it with your own domain.
    which you should configure at your DNS provider
    (it can take some time until they are public).
 
+### Docker installation
+Installation using docker compose is presented [here](./docs/DOCKER_INSTALLATION_EN.md)
+
 ### Other helpful commands
 
 To check the status of your remotely running chatmail service: