Make existing exercises less boring

[Tom-van-Woudenberg]

Right now they are factually correct but just a long list of text. Boring!

The 6 exercises part of: https://teachbooks.io/template/exercises/exercises.html
Ideas:

• Add H5P reflection question on the correct point instead of underneath as 'check understanding'
• Add screenshots (can be taken from manual: https://teachbooks.io/manual/workflows/collaboration.html). One issue was not being able to find the Actions tab (or read/navigate the contents)
• Add h5p question on what if action fail because of bad toc (typical stuff with file paths; someone also accidentally added a _ as the first character in the first line - this would be a good "challenge" exercise)
• Add H5p question on using the correct repo: not being able to find the one they created, perhaps looking in teachbooks org repos (some did PR to template, not a partner repo)