Provide empty file for learning basic syntax

[gwils]

When running the course in person, we start a new file to teach basic Haskell syntax, and encourage students to start their own file and follow along, including working in ghci.

The .ghci file in the course repo, which drives much of the course, makes this part difficult, because the course is loaded rather than a standard ghci session with the typical prelude. The students either need to make their file in a directory outside the course, or invoke ghci with the -ignore-dot-ghci flag.
It would be smoother if students never needed to be aware of this flag, and never needed to use a directory outside the course itself.

I propose we provide an empty file in a subdirectory and always encourage students to use this file for learning basic syntax.