A good way of creating a git master branch from a former one -

okay couldn't think of title this, here's story.

i made survey app specific one, odd invitation logic creating pdf @ specific parts of procedure, made master branch since small , 1 time app.

then few years later there project use app small modifications. went have problem, want have master branch work on core parts , bug fixes, other branches pull it.

the way can think of is, have move master(the first project) branch(version/aa), , remove project specific stuff on master, if pull version/aa, delete specific code branch, have manually revert code parts back, seems full of danger.

is there way it?

master name, can name branch whatever want , change meaning of name whatever prefer. master default name default branch kept branch main development happens.

you can rename existing branches using git branch -m oldname newname. , can introduce branch pointing older version using git branch branchname old-commit-hash.

so in case, create branch old point before got specific. can merge in of changes specific development make more robust. , on, can start working on core , merge changes specific release branches.