Update supporting pages

[cise-midoglu]

The proposal is to have 3 supporting pages in the study:

1. Introduction about the study (add)
2. Instructions and orientation about the rating template (add)
3. Pre-questionnaire comprising demographic questions (update)

Tentative draft: https://docs.google.com/document/d/1el-8_FcnXwyO3sT2ij9UDy-rSOe48NzrmcGuFz5LR7s/edit?usp=sharing

[davidlindero]

We decided in the Wednesday-meeting to have this introduction/pre-questionnaire in physical form instead, so it will not be implemented in avrateNG (at this time anyway). However, please keep this issue open until Friday Feb10 so the document can be reached while we are discussing it.