docs: Fix typo in "How To Start" (#111)

Co-authored-by: Christoph Bühler <[email protected]>

Author: tomkerkhove

docs/docs/getting_started.md

@@ -25,7 +25,7 @@ Using this sdk is pretty simple:
 
 - Create a new asp.net core application
 - Install the package
-- Replace the `Run` function in `Program.ch`
+- Replace the `Run` function in `Program.cs`
 - Add the operator to `Startup.cs`
 - Write entities / controllers / finalizers
 - Go.