doc: add link to contributing and licence file (#2413)

README.md

@@ -211,30 +211,13 @@ For an alternative, have a look at Yahoo's [xss-filters library](https://github.
 
 Remember, validating can be troublesome sometimes. See [A list of articles about programming assumptions commonly made that aren't true](https://github.com/jameslk/awesome-falsehoods).
 
-## License (MIT)
+## Contributing
 
-```
-Copyright (c) 2018 Chris O'Hara <[email protected]>
-
-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.
-```
+We welcome contributions from the community! If you're interested in contributing to this project, please read our [Contribution Guide](CONTRIBUTING.md) to get started.
+
+## License
+
+This project is licensed under the [MIT](LICENSE). See the [LICENSE](LICENSE) file for details.
 
 [downloads-image]: http://img.shields.io/npm/dm/validator.svg