cleanup code, migrate to modules + start rewriting ddt4all derivation

shells/ddt4all.nix

@@ -0,0 +1,51 @@
+{ pkgs, ... }:
+
+let
+	pythonWithPkgs = pkgs.python3.withPackages (ps: with ps; [
+    	ps.pyqt5
+    	ps.pyqtwebengine
+    	ps.pyusb
+    	ps.crcmod
+    	ps.pyserial
+  	]);
+in pkgs.mkShell {
+	name = "ddt4all-env";
+
+  	buildInputs = [
+    	pythonWithPkgs
+    	pkgs.qt5.qtbase
+    	pkgs.qt5.qttools
+    	pkgs.git
+    	pkgs.freetype
+    	pkgs.libGL
+    	pkgs.dbus
+    	pkgs.xorg.libX11
+    	pkgs.xorg.libXcomposite
+    	pkgs.xorg.libXdamage
+    	pkgs.xorg.libXfixes
+    	pkgs.xorg.libXrender
+    	pkgs.xorg.libXrandr
+    	pkgs.xorg.libXtst
+    	pkgs.glib
+    	pkgs.expat
+    	pkgs.fontconfig
+  	];
+
+  	nativeBuildInputs = [ pkgs.libsForQt5.qt5.wrapQtAppsHook ];
+  	shellHook = ''wrapQtAppsHook'';
+
+  	runScript = ''
+		cd $HOME/DDT4ALL
+
+    	if [ ! -d ".venv" ]; then
+      		python3 -m venv .venv
+      		source .venv/bin/activate
+      		pip install --upgrade pip
+      		pip install -r requirements.txt
+    	else
+      		source .venv/bin/activate
+    	fi
+
+    	python3 main.py
+	'';
+}