Update Studio problem templates

Many of the assessment types that can be added to an edX course supply a template. For CAPA problems, these give people a head start on the markdown needed, and can include tips, best practices, and cross-references to other information.

Things to know:

  • The templates (many of them, anyway) are in the edx-platform repo.
  • The templates are .yaml files that use HTML markup.
  • An example, .../common/lib/xmodule/xmodule/templates/problem/numericalresponse.yaml, gives you a clue as to how hard these are to find: this one is for "Numerical Input" problems.