stdlib: rename js/react.#App to js/yarn.#Package

Signed-off-by: Solomon Hykes <solomon@dagger.io>

tests/stdlib/js/yarn/testdata/package.json

@@ -0,0 +1,11 @@
+{
+  "name": "test",
+  "main": "index.js",
+  "license": {
+    "type": "Apache-2.0",
+    "url": "https://opensource.org/licenses/apache2.0.php"
+  },
+  "scripts": {
+	  "build": "mkdir -p ./build && echo output > ./build/test && touch .env && cp .env ./build/"
+  }
+}

tests/stdlib/js/yarn/yarn.cue

@@ -0,0 +1,26 @@
+package react
+
+import (
+	"dagger.io/dagger"
+	"dagger.io/js/yarn"
+	"dagger.io/alpine"
+	"dagger.io/os"
+)
+
+TestData: dagger.#Artifact
+
+TestReact: {
+	pkg: yarn.#Package & {
+		source: TestData
+	}
+
+	test: os.#Container & {
+		image: alpine.#Image & {
+			package: bash: "=5.1.0-r0"
+		}
+		mount: "/build": from: pkg.build
+		command: """
+			test "$(cat /build/test)" = "output"
+			"""
+	}
+}