fix: Replace repo for package name

[joshlynchONS]

Summary

Replace the use of repo_name for project name and package name in directory. This allows the user to create a project with a separate package and project name.

Checklists

This pull/merge request meets the following requirements:

• [ ] code runs
• [ ] developments are ethical and secure
• [ ] you have made proportionate checks that the code works correctly
• [ ] you have tested the build of the template
• [ ] test suite passes
• [ ] minimum usable documentation written in the docs folder

Comments have been added below around the incomplete checks.