Add a few more rules of thumb
An example that might help us learn how to do my-substring
Do not need additional recursion variable count, and make base case when num1 == num2
Forced this into parsable code, which clearly is not working.
But it does "something", we just don't know what yet.
Add note about when operations should not be in recursion/iteration
Moving num2 operation out of recursion (per rule just committed)
Carol suggests that perhaps this operation makes sense as the output of the base case.
We're dubious that's right, but it's worth a try.
We decided to experiment with the order of recursion vs. string building in
an attempt to fix the "order" of the string (our output looked backwards, string-wise)
This seems to have fixed that particular problem (but the code still doesn't work).
We found an off-by-one error.  This was clearly it:

We certainly don't want to recurse on num1 + 1, while in each
recursive step using the value of num1 - 1.  It just makes no
sense: we'd be getting num1 - 1 from the "previous recursive step"
anyway.