update README

- prep for public npm consumption
- simplify / rework a little

Author: ryepup

reference-lib/README.md

@@ -1,28 +1,20 @@
 # Reference Library
-NGINX directive reference in Markdown and HTML format
-
-# Installation
-
-1. Generate a github personal access token with read:packages permission
-2. Create a ~/.npmrc file with the following content
-```
-@nginxinc:registry=http://npm.pkg.github.com
-//npm.pkg.github.com/:_authToken=$TOKEN
-```
-3. Run
-```bash
-npm install --save @nginx/[email protected]
-```
-
-# Usage
-1. find
-```javascript
-import { find, Format } from '@nginx/reference-lib'
-const content = find('listen', undefined, Format.HTML)
-```
-
-2. getDirectives
-```javascript
-import { getDirectives, Format } from '@nginx/reference-lib'
-const directive = getDirectives(Format.HTML)
-```
+
+Machine-readable NGINX directive documentation, with Markdown and HTML formats.
+
+This library is generated from the official NGINX documentation, and intended for use in other tools that work with NGINX configuration files. This provides more accurate and up-to-date information than web scraping <https://nginx.org>.
+
+Every time the NGINX documentation changes, this library will be updated and published with a new version number.
+
+## Installation
+
+`npm install --save @nginx/reference-lib`
+
+## Usage
+
+We export two functions (with type definitions) to navigate the documentation:
+
+1. `getDirectives` returns a flat list of all directives in any official module
+2. `find` returns a specific directive by name
+
+See [examples](./examples) for more usage.