GitHub Backup: Update repository instructions

[mjonuschat]

Update the instructions to make the initial repository creation a smoother experience:

• Force git to use main as the branch name
• Ensure the new repository on GitHub is empty to allow successful initial pushes

[FHeilmann]

This looks like a duplicate of #393 . Maybe you could combine your efforts and put them into one of the two prs?

[hartk1213]

Yeah was just going to comment the same ..looks like a dupe of #393

[mjonuschat]

The first commit was made redundant by Eric's changes, the second commit is still valid. I'll rebase on top of #393

[EricZimmerman]

this one has a few more things about NOT creating license file etc. mjonschat and i spoke on discord and i had some time today to do some of the changes, but this is the rest. Specifically

https://github.com/VoronDesign/Voron-Documentation/pull/394/commits/6beee7a4db2af2c0ea8401a007ef85d6c9f01960

[hartk1213]

Ok sounds good 👍🏻