feat: project scaffold, version command, build

internal/version/version_test.go

@@ -0,0 +1,12 @@
+package version
+
+import "testing"
+
+func TestStringIsSemver(t *testing.T) {
+	if String == "" {
+		t.Fatal("version.String must not be empty")
+	}
+	if String[0] != 'v' {
+		t.Fatalf("version %q must start with 'v'", String)
+	}
+}