Update navigation path in README.md

This commit extends the navigation path in the README.md file to include "User Rights Assignment". This provides more precise instructions for users following the guide.

README.md

@@ -443,7 +443,7 @@ you do not need to run as Administrator to use `grcov`.
 1. Click Start, then select "Local Group Policy Editor". Or just run
    `gpedit.msc` to open it directly.
 1. In the navigation tree, select "Computer Configuration", "Windows Settings",
-   "Security Settings", "Local Policies".
+   "Security Settings", "Local Policies", "User Rights Assignment".
 1. In the pane on the right, select "Create symbolic links" and double-click it.
 1. Click "Add User or Group", and add your account.
 1. Log out and then log back in.