Improves README and add install doc page

Shows how to install as a composer dependency

docs/Install.wiki.md

@@ -0,0 +1,61 @@
+# Installation
+
+Minify requires PHP 5.3+, `git`, and `composer`.
+
+## Typical Installation
+
+Clone the project into the `min/` directory inside your document root and install its dependencies:
+
+```bash
+cd /path/to/public_html
+git clone https://github.com/mrclay/minify.git min
+cd min
+composer install --no-dev
+```
+
+**Note:** If you do this on localhost, make sure the `min/vendor/` directory gets deployed to production.
+
+## Installing as a composer dependency
+
+Add `"mrclay/minify": "~3.0.0"` to your site's composer.json, and `composer install`.
+
+The following assumes your `vendor` directory is in your document root. Adjust the `MINIFY` path as needed:
+
+```bash
+cd /path/to/public_html
+mkdir min
+MIN=min/
+MINIFY=vendor/mrclay/minify/
+cp ${MINIFY}example.index.php ${MIN}index.php
+cp ${MINIFY}.htaccess ${MIN}
+cp ${MINIFY}config.php ${MIN}
+cp ${MINIFY}groupsConfig.php ${MIN}
+cp ${MINIFY}quick-test.js ${MIN}
+cp ${MINIFY}quick-test.css ${MIN}
+```
+
+Edit `min/index.php` to remove the ``die()`` statement and adjust the `vendor` path as needed.
+
+**Note:** This does not install the [URL builder](https://github.com/mrclay/minify/blob/master/docs/BuilderApp.wiki.md), but it's not necessary for operation.
+
+## Verifing it works
+
+You can verify it works via these two URLs:
+    
+* http://example.org/min/?f=min/quick-test.js
+* http://example.org/min/?f=min/quick-test.css
+
+If your server supports mod_rewrite, the `?` are not necessary:
+
+* http://example.org/min/f=min/quick-test.js
+* http://example.org/min/f=min/quick-test.css
+
+## Having trouble?
+
+Write the [Google Group](http://groups.google.com/group/minify) for help.
+
+## More links
+
+* [Usage instructions](https://github.com/mrclay/minify/blob/master/docs/UserGuide.wiki.md)
+* [Cookbook](https://github.com/mrclay/minify/blob/master/docs/CookBook.wiki.md) for more advanced options
+* [All docs](https://github.com/mrclay/minify/tree/master/docs)