Add tutorial 0

[nitingupta910]

• Add a new branch 'tut0' for tutorial 0 (Dev test setup).
• This branch is based off the 'tut23' branch, so it inherits the CMake build system from there.
• Branches for tutorial 1, 2, ... are going to be based on this 'tut0' branch (coming soon), so will be cleaner as they will not have unrelated file removal diffs as in tut0.

[nitingupta910]

I did not want this pull request to have tut23 branch as the merge target. This is to created a new branch tut0 instead. I don't think I can create a pull request in Github targeting a new branch in upstream, so wanted to clarify the intent.

[blurrypiano]

this is a great idea! I'll see if I can do anything, or I'll create a tut0 branch and you can switch the target to there. I'll let you know when I do. Don't have time now with the holidays.