cleanup: move packages to top level, change vanity URL

Signed-off-by: Andrea Luzzardi <aluzzardi@gmail.com>

environment/environment_test.go

@@ -0,0 +1,24 @@
+package environment
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"go.dagger.io/dagger/state"
+)
+
+func TestLocalDirs(t *testing.T) {
+	st := &state.State{
+		Path: "/tmp/source",
+		Plan: "/tmp/source/plan",
+	}
+	require.NoError(t, st.SetInput("www.source", state.DirInput("/", []string{})))
+
+	environment, err := New(st)
+	require.NoError(t, err)
+
+	localdirs := environment.LocalDirs()
+	require.Len(t, localdirs, 2)
+	require.Contains(t, localdirs, "/")
+	require.Contains(t, localdirs, "/tmp/source/plan")
+}