DOCS: Create GridFS Sample with C# Driver

The MongoDB C# Driver documentation does not describe any use of the GridFS support. There are several comments on the wiki page requesting this. The only useage example that is useful in any way can be found in this SO post: http://stackoverflow.com/questions/4988436/mongodb-gridfs-with-c-how-to-store-files-such-as-images/4990536#4990536