feat: follow a RetroDECK bios folder moved alone

RetroDECK moves each of its folders on its own and records the new place
in retrodeck.json paths (api_data_processing.sh:913-935). Only
rd_home_path was read, so files went to <home>/bios after a move.

wiki/installer.md

@@ -372,7 +372,7 @@ WSL does not pass them. A forced `--platform retrobat` falls back to
 | `HKCU\SOFTWARE\RetroBat` `LatestKnownInstallPath`, which `RetroBat.exe` writes on every start (read through `reg.exe` under WSL) | RetroBat | that folder + `\bios`, before the fixed folders above |
 | `~/.config/EmuDeck/settings.sh` (Linux and macOS) | EmuDeck | `emulationPath` + `/bios` |
 | `%APPDATA%\EmuDeck\settings.ps1`, else `%USERPROFILE%\EmuDeck\settings.ps1` | EmuDeck | `$emulationPath` + `\bios`, `C:\Emulation\bios` when it names none (a network install: the `$VolName` share + `\Emulation\bios`) |
-| `~/.var/app/net.retrodeck.retrodeck/config/retrodeck/retrodeck.json` | RetroDECK | `paths.rd_home_path`, falling back to the pre-migration `retrodeck.cfg` and its `rdhome` |
+| `~/.var/app/net.retrodeck.retrodeck/config/retrodeck/retrodeck.json` | RetroDECK | `paths.rd_home_path`, falling back to the pre-migration `retrodeck.cfg` and its `rdhome`. A folder RetroDECK moved on its own is followed: files for `bios/` go to `paths.bios_path`, files for `roms/` to `paths.roms_path`, and the run names the new place |
 | `~/.var/app/org.libretro.RetroArch/config/retroarch/retroarch.cfg` | RetroArch (Flatpak) | `system_directory` |
 | `~/snap/retroarch/current/.config/retroarch/retroarch.cfg` | RetroArch (Snap) | `system_directory` |
 | `~/.config/retroarch/retroarch.cfg` | RetroArch (native) | `system_directory` |