[DOC] add demos for difficulty & discrimination prediction

[ShangziXue]

Thanks for sending a pull request! Please make sure you click the link above to view the contribution guidelines, then fill out the blanks below.

Description

add demos for difficulty & discrimination prediction

What does this implement/fix? Explain your changes.

add demos for difficulty & discrimination prediction

Pull request type

• [ ] [DATASET] Add a new dataset
• [ ] [BUGFIX] Bugfix
• [ ] [FEATURE] New feature (non-breaking change which adds functionality)
• [ ] [BREAKING] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] [STYLE] Code style update (formatting, renaming)
• [ ] [REFACTOR] Refactoring (no functional changes, no api changes)
• [ ] [BUILD] Build related changes
• [x] [DOC] Documentation content changes
• [ ] [OTHER] Other (please describe):

Changes

add demos for difficulty & discrimination prediction

Does this close any currently open issues?

No

Any relevant logs, error output, etc?

No

Checklist

Before you submit a pull request, please make sure you have to following:

Essentials

• [x] PR's title starts with a category (e.g. [BUGFIX], [FEATURE], [BREAKING], [DOC], etc)
• [x] Changes are complete (i.e. I finished coding on this PR)
• [x] All changes have test coverage and al tests passing
• [x] Code is well-documented (extended the README / documentation, if necessary)
• [x] If this PR is your first one, add your name and github account to AUTHORS.md

Comments

• If this change is a backward incompatible change, why must this change be made.
• Interesting edge cases to note here

[nnnyt]

Move your demo code to the directoryexamples/downstream/:

1. move your notebook to examples/downstream/difficulty_prediction.ipynb and examples/downstream/discrimination_prediction.ipynb
2. remove examples/diff_disc_pred/src/common.py (You can simply add the code in the beginning of your notebook).

Also, the utils fold should be moved to examples/downstream/utils.py.

[nnnyt]

Add your name and github account to AUTHORS.md, since it is your first contribution

BTW, always modify and update your code to the branch dev

[nnnyt]

Also some codes that handle the config are necessary in __init__. Please run your demo and see what other modifications are needed. Writing a correct demo is IMPORTANT for you since you need to write instructions for downstream task models in EduNLP tutorials later.