Improve Student's "Getting Started" section

- Clearer steps

- Add missing steps
Add new section about the sprint
Rewrite "Deciding What to Work On" section

- Remove content that didn't belong

- Give more details about what can be worked on

- Mention translations as a minor project
Rewrite "Stay in Touch" section

- Renamed to "Communicate"

- Removed analogy and fluff

- Be specific about communication expectations
Improve "Expectations" and remove "How to Succeed"

- Be more clear with some expectations and add new ones

- "How to Succeed" was basically covered in other sections