move contents of readme into library docs

pkg/http_server/README.md

-Library of HTTP server classes.
+# http_server
 
 This package contains a set of high-level classes that, together with
 HttpServer, makes is easy to provide content through HTTP servers.
 
-## Virtual directory
+**NOTE:** This package currently only works for
+server-side or command-line Dart applications. In other words, if the app
+imports `dart:io`, it can use this package.
 
-The VirtualDirectory class makes it possible to easy serve static content from
-the drive. It supports:
+## Using
 
- *  Range-based request, making it possible to pause/resume downloads and stream
-    videos.
- *  If-Modified-Since based caching.
- *  Automatic GZip-compression of content.
- *  Ability to follow links within, either throughout the system or in a jailed
-    root.
- *  Optional directory listing.
+Please see the [API docs][docs] for explanations and examples.
 
- The following example shows how to set up a Virtual Directory of a given path
+## Filing issues
 
-    var virtualDirectory = new VirtualDirectory('/var/www/');
-    virtualDirectory.serve(new HttpServer('0.0.0.0', 8080));
+Please file issues for the http package at [http://dartbug.com/new][bugs].
 
-See [VirtualDirectory](
-http://api.dartlang.org/docs/http_server/VirtualDirectory.html)
-for more info about how to customize the class.
-
-## Virtual host
-
-The VirtualHost class makes it possible to serve multiple hosts on the same
-address, by using the `Host` field of the incoming requests. It also provides
-the ability to work on wildcards for sub-domains.
-
-    var virtualHost = new VirtualHost(server);
-    // Filter out on a specific host
-    var stream1 = virtualServer.addHost('static.myserver.com');
-    // Wildcard for any other sub-domains.
-    var stream2 = virtualServer.addHost('*.myserver.com');
-    // Requets not matching any hosts.
-    var stream3 = virtualServer.unhandled;
-
-See [VirtualHost](
-http://api.dartlang.org/docs/http_server/VirtualHost.html)
-for more information.
+[bugs]: http://dartbug.com/new
+[docs]: https://api.dartlang.org/docs/channels/stable/latest/http_server.html