Add LICENSE and CODE_OF_CONDUCT

Add [LICENSE](/LICENSE) and [CODE_OF_CONDUCT.md](/CODE_OF_CONDUCT.md)
from [thoughtbot/templates][].

[thoughtbot/templates]: https://github.com/thoughtbot/templates

Author: seanpdoyle

CODE_OF_CONDUCT.md

@@ -0,0 +1,6 @@
+# Code of conduct
+
+By participating in this project, you agree to abide by the
+[thoughtbot code of conduct][1].
+
+[1]: https://thoughtbot.com/open-source-code-of-conduct

LICENSE

@@ -0,0 +1,19 @@
+Copyright (c) 2021 Sean Doyle and thoughtbot, inc.
+
+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

@@ -134,3 +134,25 @@ and include the value:
   <a class="aria-current-page:font-bold" href="/about">About us</a>
 </nav>
 ```
+
+## License
+
+tailwindcss-aria-attributes is Copyright (c) 2021 thoughtbot, inc.
+It contains free software that may be redistributed
+under the terms specified in the [LICENSE] file.
+
+[LICENSE]: /LICENSE
+
+## About
+
+![thoughtbot](http://presskit.thoughtbot.com/images/thoughtbot-logo-for-readmes.svg)
+
+This project is maintained and funded by thoughtbot, inc.
+The names and logos for thoughtbot are trademarks of thoughtbot, inc.
+
+We love open source software!
+See [our other projects][community]
+or [hire us][hire] to help build your product.
+
+[community]: https://thoughtbot.com/community?utm_source=github
+[hire]: https://thoughtbot.com/hire-us?utm_source=github