Update files

readme.markdown

@@ -0,0 +1,29 @@
+# Creative Commons 4.0 Markdown
+
+On November 25th, 2013, [Creative Commons](http://creativecommons.org/) announced their next generation licenses: [Creative Commons 4.0](https://creativecommons.org/weblog/entry/40768). By default, these are available as [HTML](http://creativecommons.org/licenses/) or [plaintext](http://creativecommons.org/weblog/entry/41127). This project adds [Markdown](http://daringfireball.net/projects/markdown/)-formatted licenses to that list.
+
+Unfortunately, the output currently varies on different Markdown viewers, in particular when it comes to indentation levels. If you any suggestion on the formatting, feel invited to contribute.
+
+## Licenses
+
+* `BY` [Attribution](licenses/by.markdown)
+* `BY-NC` [Attribution-NonCommercial](licenses/by-nc.markdown)
+* `BY-NC-ND` [Attribution-NonCommercial-NoDerivatives](licenses/by-nc-nd.markdown)
+* `BY-NC-SA` [Attribution-NonCommercial-ShareAlike](licenses/by-nc-sa.markdown)
+* `BY-ND` [Attribution-NoDerivatives](licenses/by-nd.markdown)
+* `BY-SA` [Attribution-ShareAlike](licenses/by-sa.markdown)
+* `C0` [CC0 1.0](licenses/zero.markdown)
+
+## File extension
+
+There's a plethora of Markdown file extensions, but I have decided to go with `markdown`. Read why:
+
+*"We no longer live in a 8.3 world, so we should be using the most descriptive file extensions. It’s sad that all our operating systems rely on this stupid convention instead of the better creator code or a metadata model, but great that they now support longer file extensions."*  
+Hilton Lipschitz ([via](http://hiltmon.com/blog/2012/03/07/the-markdown-file-extension/))
+
+*"…the only file extension I would endorse is “.markdown”, for the same reason offered by Hilton Lipschitz"*  
+John Gruber, creator of Markdown ([via](http://daringfireball.net/linked/2014/01/08/markdown-extension))
+
+## Contribute
+
+If you notice any mistakes in content or formatting, please send a pull request with your correction.