`git reset --hard master~1` rather than `git reset --hard a13b85e`

Using `git reset --hard master~1` rather than `git reset --hard a13b85e` to make the use of `git log` unnecessary

In the paragraph `commit-wrong-branch` you suggest to reset the branch `master` to its previous commit by using a `git log` and then resetting `master` to the `sha1` of the previous commit.

I think a simpler `git reset --hard master~1` is more convenient, since it saves the user from reading the output of `git log` and from copying the `sha1` of the commit.