New datateam training updates

[laijasmine]

• Some commonly asked questions (eg. opening netcdf files, updating system metadata) that might be resolved if the book was organized better

Add additional resources or better targeted modules to help complete the tasks

• Larger datasets now require more skills with things like writing a simple loop -> add more support there
• For dealing with large attribute tables - Alison Horst’s dplyr learnr tutorial

Add feedback to exercises to indicate that they are on the right track on the training

• Have a sample complete dataset?
• Adding Learnr iframes? (and examples)