update clone urls INSTALL.md

[jaelynlitz]

Merge request type

• New feature
• Resolves bug
• Documentation
• Other

Relates to

• OPFLOW
• SOPFLOW
• SCOPFLOW
• TCOPFLOW
• CMake build system
• Spack configuration
• Manual
• Web docs
• Other

This MR updates

• Header files
• Source code
• CMake build system
• Spack configuration
• Web docs
• Manual
• Other

Summary

fix code block links to use the github instead of gitlab

Linked Issue(s)

closes #116

[jaelynlitz]

probably need to add git submodule update --init --recursive to our instructions

[cameronrutherford]

LGTM - going to merge even though CI is failing since this is just cosmetic