Tutorial 3 pre-flight checklist 2023

[mpjashby]

• Add walk-through videos
• Add questions
• Add further reading
• Add concluding message with thumbs up emoji
• Make sure tutorial (or section) starts with the final map that we'll create
• Make sure tutorial finishes with a complete script
• Check that comments have initial caps
• Reduce image sizes using harmonise_image_sizes()
• Spell check
• Add css: ["css/tutorial_style.css", "css/2023.css"]
• Increment package version number
• Check all code in RStudio Server
• Update Moodle