add command for powershell

Author: XChaitanyaX

getting-started/git-boot-camp.rst

@@ -461,12 +461,19 @@ If you don't have GitHub CLI or hub installed, you can set up a git alias:
 
       $ git config --global alias.pr '!sh -c "git fetch upstream pull/${1}/head:pr_${1} && git checkout pr_${1}" -'
 
-.. tab:: Windows
+.. tab:: Windows cmd
 
    .. code-block:: dosbatch
 
       git config --global alias.pr "!sh -c 'git fetch upstream pull/${1}/head:pr_${1} && git checkout pr_${1}' -"
 
+.. tab:: Windows Powershell
+
+   .. code-block:: shell
+
+      git config --global alias.pr '!f() { git fetch upstream pull/$1/head:pr_$1 && git checkout pr_$1; }; f'
+
+
 The alias only needs to be done once.  After the alias is set up, you can get a
 local copy of a pull request as follows::