title: Generate class inside a subfolder using t4 template
body: <p>I am generating context of my entities using T4 templates. When t4 template file runs, it adds generated files in project root directory. What I want is that generated files are placed under a sub folder. If sub-folder is not present then create folder and then place generated files inside that. And if file is present then new file doesn't generate.</p>
  
  <p>I am new to t4 templates. I replaced </p>
  
  <pre><code>fileManager.StartNewFile(entity.Name + ".cs");
  </code></pre>
  
  <p>to</p>
  
  <pre><code>fileManager.StartNewFile("SubFolder\" + entity.Name + ".cs");
  </code></pre>
  
  <p>When I run it, file is created in SubFolder (Open folder using windows explorer) but project is not aware of it. And if there is no folder then strange behavior occurs. What am I missing?</p>