Demo 2.5

1

git init
echo c1 > c1.md
git add *
git commit -m"c1"

2

git switch -c work

3

echo cc >> c1.md
git add *
git commit -m"c1"

4

git switch master
git merge work
git switch work

Go back to 3

Alternative:

Do #3 5 times, then do #4