ER: Update Prework Template

### Emergent Requirement - Problem
roster task item in the prework does not specify that if I am both front end and back end I should choose full stack.

### Issue you discovered this emergent requirement in
- #6628

### Date discovered
2024-04-14

### Did you have to do something temporarily
- [ ] YES
- [x] NO

### Who was involved
@kellyc9

### What happens if this is not addressed
Some people are confused.

### Resources
[team roster](https://docs.google.com/spreadsheets/d/11u71eT-rZTKvVP8Yj_1rKxf2V45GCaFz4AXA7tS_asM/edit#gid=0)

### Recommended Action Items
- [x] Make a new issue
- [ ] Discuss with team
- [ ] Let a Team Lead know

### Potential solutions [draft]
Add text to the line that currently says
>- [ ] Add yourself to the [team roster](https://docs.google.com/spreadsheets/d/11u71eT-rZTKvVP8Yj_1rKxf2V45GCaFz4AXA7tS_asM/edit#gid=0)

so that it says
- [ ] Add yourself to the [team roster](https://docs.google.com/spreadsheets/d/11u71eT-rZTKvVP8Yj_1rKxf2V45GCaFz4AXA7tS_asM/edit#gid=0). If you are both front and back end, choose Full Stack under Role(s)