Change Submodule references from git to HTTPS

[Sewer56]

Bug Report

Summary

Projects which derive from this repository require an SSH key to clone with submodules. We've abolished this policy on repositories a while back, and individually reverted repositories to nod do this, however the template repository hasn't been updated to reflect this.

Steps to reproduce

1. Attempt to clone the repository with submodules.
2. Observe that it requests an SSH key.

What is the expected behaviour?

Cloning the repository with submodules should not require an SSH key, allowing for a smoother and more accessible work experience for both internal and external contributors.