feat: find RetroBat through the folder it records

RetroBat.exe writes its folder to HKCU\SOFTWARE\RetroBat
LatestKnownInstallPath on every start (retrobat-executable 702da66a,
Program.cs:57 and 99, RegistryTools.cs:15-50). Only C:\RetroBat and the
profile folder were looked at, so an install on D: was missed and a forced
--platform retrobat wrote into C:\RetroBat\bios. The value is read
through winreg, or reg.exe under WSL, before the fixed folders.

install.sh

@@ -18,7 +18,7 @@ esac
 TEMP_INSTALLER=""
 TEMP_DIRECTORY=""
 DEFAULT_INSTALL_URL="https://raw.githubusercontent.com/Abdess/retrobios/main/install.py"
-DEFAULT_INSTALL_SHA256="caec72e5ebd146509e3b1fabc7d8d4c5c921567592d6d1581df6e5cc50f3e96f"
+DEFAULT_INSTALL_SHA256="f05f862fcebc16e99d692a20a09163665828ea0383643fcc96a41b11d77fcff7"
 MAX_INSTALLER_BYTES=2097152
 
 cleanup() {