Sail Separate integration docs added

source/docs/v3/integrations/sail.blade.md

@@ -0,0 +1,40 @@
+---
+title: Laravel Sail integration
+extends: _layouts.documentation
+section: content
+---
+
+# Laravel Sail {#sail}
+
+## Central domains
+
+If you're using Laravel Sail, no changes are needed, default values are good to go:
+
+```php
+// config/tenancy.php
+
+'central_domains' => [
+    '127.0.0.1',
+    'localhost',
+],
+```
+
+## Creating tenants
+
+Before creating any tenants you have to ensure that the `sail` user has the necessary permissions.
+
+To do so either login to the mysql shell or via any client using root user credentials and run the following queries:
+
+```bash
+GRANT ALL PRIVILEGES on *.* to 'sail'@'%';
+FLUSH PRIVILEGES;
+```
+
+If you are using [Database Customization]({{ $page->link('customizing-databases') }}), then you will have add the following GRANT as well:
+
+```bash
+GRANT GRANT OPTION on central_database.* to 'sail'@'%';
+FLUSH PRIVILEGES;
+```
+
+This grant allows the central database to grant permissions to other users.