Tutorial needs updating

[0xrgg]

This is less of an issue for me now but I was just working through your tutorial and noticed there are inconsistencies what's on the tutorial vs the code here makes it difficult when you encounter errors... Obviously this is due to code being refactored and what not but for people new to the language and the model such as myself, this is quite difficult when it comes to debugging.

I must admit, some of my errors were typos or autocorrect issues but this was more difficult than it could have been due to the quoted code differing from what exists here now.

Even the simple typeof(Startup) issue had my Googling the answer only to find that it was here in the code.