Update 02-setup.md

Add config to set default branch to main, also updating color.ui

_episodes/02-setup.md

@@ -27,7 +27,8 @@ Jane sets up her new laptop:
 ~~~
 $ git config --global user.name "Jane Smith"
 $ git config --global user.email "[email protected]"
-$ git config --global color.ui "auto"
+$ git config --global color.ui auto
+$ git config --global init.defaultBranch main
 ~~~
 {: .bash}