title: Load from text file at program startup
body: <p>Sorry for the likely noobish question, just starting to learn c#, and couldn't find anything that worked.</p>
  
  <p>I'm making a text editor in c#, and so far it can open and save text files from inside the program with dialogs, but how can I make it load the text from a file that I open in windows explorer, outside of the editor, with the editor</p>
  
  <p>Basically, I can already read from text files opened inside the editor, but how can i make it so that if I open a text file (and have the default program for opening text files set to my editor), it'll read it?</p>
  
  <p>I saw something about getting the filename somehow and passing it as an argument, if that helps.</p>