update readme

README.md

@@ -1,24 +1,54 @@
-# Node.js Language Pack
+Heroku buildpack: Node.js
+=========================
 
-The Node.js Language Pack will run `npm install` on your app after setting
-up an appropriate environment of [node](http://github.com/joyent/node),
-[npm](https://github.com/isaacs/npm) and [SCons](http://www.scons.org).
+This is a [Heroku buildpack](#) for Node.js apps.  It uses [NPM](#) and [SCons](#).
 
-The `node_modules` directory will be cached between builds to allow for
-faster `npm install` time.
+Usage
+-----
 
-## Usage
+Example usage:
 
-Add this language pack to your `LANGUAGE_PACK_URL`.
+    $ ls
+    Procfile  package.json  web.js
 
-    heroku config:add LANGUAGE_PACK_URL="http://github.com/heroku/language-pack-nodejs.git"
+    $ heroku create --stack cedar --buildpack http://github.com/heroku/heroku-buildpack-nodejs.git
 
-## Vendored Libraries
+    $ git push heroku master
+    ...
+    -----> Heroku receiving push
+    -----> Fetching custom buildpack
+    -----> Node.js app detected
+    -----> Vendoring node 0.4.7
+    -----> Installing dependencies with npm 1.0.8
+           express@2.1.0 ./node_modules/express
+           ├── mime@1.2.2
+           ├── qs@0.3.1
+           └── connect@1.6.2
+           Dependencies installed
 
-The versions of node, npm and SCons used by the language pack are controlled
-by the constants `NODE_VERSION`, `NPM_VERSION`, and `SCONS_VERSION` in
-`bin/compile`
+The buildpack will detect your app as Node.js if it has the file `package.json` in the root.  It will use NPM to install your dependencies, and vendors a version of the Node.js runtime into your slug.  The `node_modules` directory will be cached between builds to allow for faster NPM install time.
 
-To use different versions of these tools, you can use the helper scripts
-`support/package_node` and `support/package_npm`. These support scripts will
-create binary tarballs that can be referenced by `bin/compile`.
+Hacking
+-------
+
+To use this buildpack, fork it on Github.  Push up changes to your fork, then create a test app with `--buildpack <your-github-url>` and push to it.
+
+To change the vendored binaries for Node.js, NPM, and SCons, use the helper scripts in the `support/` subdirectory.  You'll need an S3-enabled AWS account and a bucket to store your binaries in.
+
+For example, you can change the vendored version of Node.js to v0.5.8.
+
+First you'll need to build a Heroku-compatible version of Node.js:
+
+    $ export AWS_ID=xxx AWS_SECRET=yyy S3_BUCKET=zzz
+    $ s3 create $S3_BUCKET
+    $ support/package_node 0.5.8
+
+Open `bin/compile` in your editor, and change the following lines:
+
+    NODE_VERSION="0.5.8"
+
+    S3_BUCKET=zzz
+
+Commit and push the changes to your buildpack to your Github fork, then push your sample app to Heroku to test.  You should see:
+
+    -----> Vendoring node 0.5.8