Create note for git switch

Git 2.23 comes with the experimental command `git switch`.
This commit adds a note with the most common operations that readers will want to use `git switch` for.

Author: HonkingGoose

book/03-git-branching/sections/nutshell.asc

@@ -198,3 +198,12 @@ Let's see why you should do so.
 ====
 It's typical to create a new branch and want to switch to that new branch at the same time -- this can be done in one operation with `git checkout -b <newbranchname>`.
 ====
+
+[NOTE]
+====
+From Git version 2.23 onwards you can use `git switch` instead of `git checkout` to:
+
+- Switch to an existing branch: `git switch testing-branch`.
+- Create a new branch and switch to it: `git switch -c new-branch`. The `-c` flag stands for create, you can also use the full flag: `--create`.
+- Return to your previously checked out branch: `git switch -`.
+====