writing storage drivers section

navigation.php

@@ -27,6 +27,7 @@ return [
             'Custom Database Names'    => 'docs/custom-database-names',
             'Tenancy Initialization'   => 'docs/tenancy-initialization',
             'Filesystem Tenancy'       => 'docs/filesystem-tenancy',
+            'Writing Storage Drivers'  => 'docs/writing-storage-drivers',
             'Development'              => 'docs/development',
         ],
     ],

source/docs/writing-storage-drivers.md

@@ -0,0 +1,73 @@
+# Writing Storage Drivers
+
+If you don't want to use the provided DB/Redis storage drivers, you can write your own driver.
+
+To create a driver, create a class that implements the `Stancl\Tenancy\Interfaces\StorageDriver` interface.
+
+For historical reasons, the `TenantManager` will try to json encode/decode data coming from the storage driver. If you want to avoid this, set `public $useJson = false;`. That will make `TenantManager` encode/decode only `put()` and `get()` data, so that data types can be stored correctly.
+
+The DB storage driver has `public $useJson = false;`, while the Redis storage driver doesn't use this property, so it's false by default.
+
+Here's an example:
+
+```php
+
+namespace App\StorageDrivers\MongoDBStorageDriver;
+
+use Stancl\Tenancy\Interfaces\StorageDriver;
+
+class MongoDBStorageDriver implements StorageDriver
+{
+    public $useJson = false;
+
+    public function identifyTenant(string $domain): array
+    {
+        //
+    }
+
+    public function getAllTenants(array $uuids = []): array
+    {
+        //
+    }
+
+    public function getTenantById(string $uuid, array $fields = []): array
+    {
+        //
+    }
+
+    public function getTenantIdByDomain(string $domain): ?string
+    {
+        //
+    }
+
+    public function createTenant(string $domain, string $uuid): array
+    {
+        //
+    }
+
+    public function deleteTenant(string $uuid): bool
+    {
+        //
+    }
+
+    public function get(string $uuid, string $key)
+    {
+        //
+    }
+
+    public function getMany(string $uuid, array $keys): array
+    {
+        //
+    }
+
+    public function put(string $uuid, string $key, $value)
+    {
+        //
+    }
+
+    public function putMany(string $uuid, array $values): array
+    {
+        //
+    }
+}
+```