build: simplify compiler package setup

packages/compiler/.npmignore

@@ -0,0 +1,3 @@
+__tests__/
+__mocks__/
+dist/packages

packages/compiler/README.md

@@ -0,0 +1 @@
+# @vue/compiler

packages/compiler/index.js

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+'use strict'
+
+if (process.env.NODE_ENV === 'production') {
+  module.exports = require('./dist/compiler.cjs.prod.js')
+} else {
+  module.exports = require('./dist/compiler.cjs.js')
+}

packages/compiler/package.json

@@ -0,0 +1,21 @@
+{
+  "name": "@vue/compiler",
+  "version": "3.0.0-alpha.1",
+  "description": "@vue/compiler",
+  "main": "index.js",
+  "module": "dist/compiler.esm-bundler.js",
+  "typings": "dist/index.d.ts",
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/vuejs/vue.git"
+  },
+  "keywords": [
+    "vue"
+  ],
+  "author": "Evan You",
+  "license": "MIT",
+  "bugs": {
+    "url": "https://github.com/vuejs/vue/issues"
+  },
+  "homepage": "https://github.com/vuejs/vue/tree/dev/packages/compiler#readme"
+}