chore(readme): Minor cleanup

README.md

@@ -56,7 +56,6 @@ Bazzite is built from [ublue-os/main](https://github.com/ublue-os/main) and [ubl
 - Uses [Google's BBR TCP congestion control](https://github.com/google/bbr) by default.
 - [Input Remapper](https://github.com/sezanzeb/input-remapper) preinstalled and enabled. <sub><sup>(Available but default-disabled on the Deck variant, may be enabled with `ujust restore-input-remapper`)</sup></sub>
 - Bazzite Portal provides an easy way to install numerous applications and tweaks, including installing [LACT](https://github.com/ilya-zlobintsev/LACT) and [GreenWithEnvy](https://gitlab.com/leinardi/gwe).
-- [Nix](https://nixos.org/) package manager with [Fleek](https://getfleek.dev/) optionally available for install via `ujust`.
 - [Brew](https://brew.sh/) package manager optionally available for install via Bazzite Portal.
 - [Waydroid](https://waydro.id/) preinstalled for running Android apps. Set it up with this [quick guide](https://universal-blue.discourse.group/docs?topic=32).
 - Manage applications using [Flatseal](https://github.com/tchx84/Flatseal), [Warehouse](https://github.com/flattool/warehouse), and [Gear Lever](https://github.com/mijorus/gearlever).
@@ -111,7 +110,7 @@ Variant designed for usage as an alternative to SteamOS on the Steam Deck, and f
 - Comes with patches from [SteamOS BTRFS](https://gitlab.com/popsulfr/steamos-btrfs) for full BTRFS support for the SD card by default.
 - Ships with a ported copy of [SDGyroDSU](https://github.com/kmicki/SteamDeckGyroDSU), enabled by default.
 - Option to install [Decky Loader](https://github.com/SteamDeckHomebrew/decky-loader), [EmuDeck](https://www.emudeck.com/), [RetroDECK](https://retrodeck.net/), and [ProtonUp-Qt](https://davidotek.github.io/protonup-qt/), among numerous other useful packages on installation.
-- Custom update system allows for the OS, Flatpaks, Nix packages <sup><sub>(Via Fleek)</sub></sup>, and Distrobox images to be updated directly from the Game mode UI.
+- Custom update system allows for the OS, Flatpaks, and Distrobox images to be updated directly from the Game mode UI powered by [ublue-update](https://github.com/ublue-os/ublue-update) and [topgrade](https://github.com/topgrade-rs/topgrade).
 - Built in support for Windows dual-boot thanks to Fedora's installation of GRUB being left intact.
 - Update break something? Easily roll back to the previous version of Bazzite thanks to `rpm-ostree`'s rollback functionality. You can even select previous images at boot.
 - Steam and Lutris preinstalled on the image as layered packages.