Use 'branch' instead of 'checkout -b'

[Plsr]

Referencing to I committed to master instead of a new branch here.

Instead of using

(master)$ git checkout -b my-branch
(my-branch)$ git checkout master
(master)$

just using

(master)$ git branch my-branch

works as well.

This was actually changed before in #21 but got mixed up a little. Now, not only are the commands somewhat repetitive, but also it's a little confusing because the explanation states

Create the new branch while remaining on master:

which is not exactly what is happening with these commands.

[Plsr]

Did look around a little, looks like the revert to the old commands happened in #47 since 978e484 and 88252b2 are almost a year apart (#21 was merged between them) and the latter seems to be based on an old README.md.

I guess the revert to the old commands happened by accident then, rather than on purpose.

[RichardLitt]

I did not know this!

Sorry about the mixup. Thank you for finding this.