ICM: Strategies section example added.

Author: dmitry-ivanov

README.md

@@ -43,3 +43,16 @@ Overlapping can be prevented by various strategies:
 
 Default `file` strategy is fine for a small applications, which are deployed on a single server.
 If your application is more complex and, for example, is deployed on a several nodes, then you probably would like to use some other mutex strategy.
+
+You can change mutex strategy for your console command by specifying `$mutexStrategy` field:
+
+```php
+class Foo extends Command
+{
+    use WithoutOverlapping;
+
+    protected $mutexStrategy = 'mysql';
+
+    // ...
+}
+```