Use ShellCheck for CI about main

[prplwtf]

Thank you for the suggestion, I've installed ShellCheck and it appears that there are indeed a lot of problems with blueprint.sh.

I'll be slowly going over these when I have the time to do so. I'll leave this issue open until most (if not all) issues are resolved.

[prplwtf]

@devnote-dev I've gone through every single advisory on blueprint.sh and added a .shellcheckrc file for the issues that cannot be fixed due to file/code structure regarding the development file tree.

I might need to go through a few of Blueprint's libraries in the coming days, hence why I'm keeping this Issue open for now.

thank you shellcheck vscode extension for making my life easier

[prplwtf]

I'll re-add this issue to the "Framework Progress Board" as I'm trying to have a better overview of current issues/bugs/to-do-things.

[prplwtf]

@devnote-dev There we go, I've now gone through (and tested) all of Blueprint's shell libraries with ShellCheck, which means, this issue can now finally be closed.