Add license file

Fixes webpack#663

LICENSE

@@ -0,0 +1,22 @@
+(The MIT License)
+
+Copyright (c) 2012-2016 Tobias Koppers
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+'Software'), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

README.md

@@ -47,12 +47,6 @@ When making a PR, keep these goals in mind:
 - Processing options and stats display is delegated to webpack, so webpack-dev-server/middleware should not do much with it. This also helps us to keep up-to-date with webpack updates.
 - The workflow should be to start webpack-dev-server as a separate process, next to the "normal" server and to request the script from this server or to proxy from dev-server to "normal" server (because webpack blocks the event queue too much while compiling which can affect "normal" server).
 
-## License
-
-Copyright 2012-2016 Tobias Koppers
-
-[MIT](http://www.opensource.org/licenses/mit-license.php)
-
 [npm]: https://img.shields.io/npm/v/webpack-dev-server.svg
 [npm-url]: https://npmjs.com/package/webpack-dev-server