docs: require Buildx

CONTRIBUTING.md

@@ -14,7 +14,7 @@ SPDX-License-Identifier: MIT
 
 ## Dev Setup
 ### Prerequisits
-- Docker or Podman (not tested)
+- Docker with Buildx or Podman (not tested)
 - For VS Code the [Dev Containers extension](https://marketplace.visualstudio.com/items?itemName=ms-vscode-remote.remote-containers)
 
 ### VS Code

README.md

@@ -19,7 +19,7 @@ This repository contains following projects:
 - **daemon**: a server side backend application that handles all the repository work aspects.
 - **frontend**: a client web application allowing users to interact with the server in a convenient manner.
 
-### Features:
+## Features
 
 - **Clear Structure**: Box consists of sections, a branch/repository/architecture triplet (e.g., stable/core/x86_64) allowing straightforward navigation in a file manager-like UI;
 - **Simple Package Management**: packages can be added, removed and updated using a plain drag-and-drop;
@@ -28,9 +28,9 @@ This repository contains following projects:
 - **User Management**: bxt is made to have a hierarchical multi-user system with per-user granular permission control;
 - **Candidates System**: the package's source (either sync or manual/automatic push) preference is fully configurable;
 
-### Setup:
+## Setup
 
-To build and run this application you can use Docker
+To build and run this application you can use Docker (with Buildx):
 
 ```bash
 # copy example configs