Add .d.ts file to astro package for language-tools consumption (#2711)

* Add .d.ts file for user and language-server consumption

* Update according to feedback

packages/astro/env.d.ts

@@ -0,0 +1,12 @@
+/// <reference types="vite/client" />
+
+type Astro = import('./dist/types/@types/astro').AstroGlobal;
+
+// We duplicate the description here because editors won't show the JSDoc comment from the imported type (but will for its properties, ex: Astro.request will show the AstroGlobal.request description)
+/**
+ * Astro.* available in all components
+ * Docs: https://docs.astro.build/reference/api-reference/#astro-global
+ */
+declare const Astro: Readonly<Astro>;
+
+declare const Fragment: any;

packages/astro/package.json

@@ -15,6 +15,7 @@
   "types": "./dist/types/@types/astro.d.ts",
   "exports": {
     ".": "./astro.js",
+    "./env": "./env.d.ts",
     "./app/node": "./dist/core/app/node.js",
     "./client/*": "./dist/runtime/client/*",
     "./components": "./components/index.js",
@@ -44,6 +45,7 @@
     "components",
     "dist",
     "astro.js",
+    "env.d.ts",
     "README.md",
     "vendor"
   ],