Fix translation of title "Git in PowerShell" to maintain consistency

Author: Integral-Tech

book/A-git-in-other-environments/sections/powershell.asc

@@ -1,5 +1,5 @@
 [[_git_powershell]]
-=== Git 在 PowerShell 中使用 Git
+=== PowerShell 中的 Git
 
 (((PowerShell)))(((tab completion, PowerShell)))(((shell prompts, PowerShell)))
 (((posh-git)))