docs: update WSL guide with new Git For Windows path

Update WSL guide to reflect GCM's move from the libexec/git-core directory
in Git for Windows to the bin directory.

Author: ldennington

docs/wsl.md

@@ -22,7 +22,7 @@ _Inside your WSL installation_, run the following command to set GCM as the Git
 credential helper:
 
 ```shell
-git config --global credential.helper "/mnt/c/Program\ Files/Git/mingw64/libexec/git-core/git-credential-manager-core.exe"
+git config --global credential.helper "/mnt/c/Program\ Files/Git/mingw64/bin/git-credential-manager-core.exe"
 ```
 
 If you intend to use Azure DevOps you must _also_ set the following Git