Add initial instructions to README (#3)

* Add initial instructions to README

* more concrete

* address comments

* link preliminary api docs

* more general

Author: dcodeIO

README.md

@@ -1,4 +1,52 @@
 ![AS](https://avatars1.githubusercontent.com/u/28916798?s=48) node
 ======================
 
-Implementations of the node.js APIs using wasi for use with AssemblyScript.
+Implementations of the node.js APIs for AssemblyScript, utilizing [WASI](https://wasi.dev).
+
+Introduction
+------------
+
+This library aims to provide a convenient node.js-like environment for AssemblyScript programs.
+Please note that it is still in its early stages and that both the library and WASI are not even
+close to be finalized.
+
+As always, if the idea sounds appealing to you, feel free to improve existing APIs or to contribute
+additional ones.
+
+Instructions
+------------
+
+Install the library components as a dependency of your project
+
+```
+$> npm install --save-dev AssemblyScript/node
+```
+
+and include it in your build step to gain access to the implementations it provides:
+
+```
+$> asc --lib ./node_modules/@assemblyscript/node/assembly [...]
+```
+
+Doing so will automatically register common globals like the `Buffer` class and enables requiring
+for example the filesystem module through `import * as fs from "fs"`.
+
+Documentation
+-------------
+
+* [Status and API documentation on the wiki](https://github.com/AssemblyScript/node/wiki)
+* [Implementation sources](./assembly)
+
+Building
+--------
+
+To run the tests, first make sure that development dependencies are installed, then run:
+
+```
+$> npm test
+```
+
+One of the dependencies is [node-wasi](https://github.com/devsnek/node-wasi), which is a native
+module. If you are running into issues when compiling it (on Windows), make sure that node-wasi
+supports your version of node.js, that your machine can build native modules in the first place
+and that your version of npm is recent (`npm install npm@latest -g`).

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@assemblyscript/node",
-  "description": "Implementations of the node.js APIs for use with AssemblyScript.",
+  "description": "Implementations of the node.js APIs for AssemblyScript, utilizing WASI.",
   "version": "0.1.0",
   "license": "Apache-2.0",
   "types": "assembly/node.d.ts",