update readme

README.md

@@ -38,6 +38,7 @@ Linux: `ln -s /path/to/frontend/build /path/to/backend/files/build`
 Windows (admin cmd) `mklink /D C:\Path\To\Backend\files\build C:\Path\To\Frontend\build`  
 
 ## Src directory structure  
+<pre>
 /controller: Main controller, takes care of sharding and the shard life-cycles. Also instantiates the master process  
     /commands: Commands you can issue to the controller  
 /server: Code running on the shards, most of the functionality lives here  
@@ -49,6 +50,7 @@ Windows (admin cmd) `mklink /D C:\Path\To\Backend\files\build C:\Path\To\Fronten
     /structures: Abstractions for various API entities, e.g. user & role  
 /util: Shared utility functionality & misc stuff  
     /errors: Error classes  
+</pre>
 
 ## TODO  
 - Dependency injection for structures, such as User.