[feat] added environment files

.envrc

@@ -0,0 +1,3 @@
+use_nix
+export GOPATH=$HOME
+export APPVM_CONFIGS=$PWD

shell.nix

@@ -0,0 +1,4 @@
+{ pkgs ? import <nixpkgs> {} }:
+with pkgs; mkShell {
+  buildInputs = [ go gocode virt-viewer virtmanager ];
+}